Re: [Tutor] Reading/dealing/matching with truly huge (ascii) files
On 22/02/12 05:44, Elaina Ann Hyde wrote: file is enormous, has over 50,000 rows and about 20 columns. On modern computers its not that enormous - probably around 10M? But there are techniques for this which we can cover another time is you do hit files bigger than fit in memory. I didn't go through the code in detail. but... e = 0.01 if i != j and Radeg[i] = (Radeg2[j]+e) and Radeg[i] = (Radeg2[j]-e) and Decdeg[i] = (Decdeg2[j]+e) and Decdeg[i] = (Decdeg2[j]-e): Using e helps tune the precision as needed. That layout style will help you see the logic more easily. But in Python you can tidy that up even more by rewriting it like if i != j and (Radeg2[j]-e) = Radeg[i] = (Radeg2[j]+e) and (Decdeg2[j]-e) = Decdeg[i] = (Decdeg2[j]+e): And you could put it in a function to further control readability of the main program and encapsulate the tests. def rowsEquate(row1,row2, i, j):... if i != j and rowsEquate(Radeg,Radeg2,i,j) and rowsEquate(Deceg, Deceg2,i,j): fopen.write( .join([str(k) for k in list(dat[i])])+ + .join([str(k) for k in list(dat[j])])+\n) I may be wrong but it looks like something wrong with the quoting there? The last quote on the first line, after the +? --- Now this is where I had to stop, this is way, way too long and messy. Its not really that long or messy, but it could be tidied up a little. did a similar approach with smaller (9000 lines each) files and it worked but took awhile, This might be the biggest problem, it will take a long time on big files. Personally I would tend to tackle a problem like this using a database and write a query to select the rows that match in one operation. Especially if I had to process a lot of files. -- Alan G Author of the Learn to Program web site http://www.alan-g.me.uk/ ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Pyhton editor
On 22/02/12 04:00, ken brockman wrote: Being a neophyte to Python, I was under the impression that you had to install tkinter independently.of python. No, its part of the standard library. On some *nix installs tk support is not compiled in but tkinter should be there. But on Windows its always there. Running it in a separate thread sounds like what this feature is doing. But IDLE has been doing that for the last several releases too (since v2.5?) -- Alan G Author of the Learn to Program web site http://www.alan-g.me.uk/ ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Reading/dealing/matching with truly huge (ascii) files
Hi Elaina, On 22 February 2012 05:44, Elaina Ann Hyde elainah...@gmail.com wrote: #select the value if it is very, very, very close if i != j and Radeg[i] = (Radeg2[j]+0.01) and Radeg[i] Alan's pretty much said what I was thinking, but I have an additional question/concern: Why do you include the i != j condition in your if statement? This is saying that you never want to compare entries from the 2 files if they're on the same row number? Is that actually intentional and correct or not? (It seems somehow wrong to me since you've not said anything about it in your post, and everything else suggests you're comparing only the data values to select your output records...) Walter ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Reading/dealing/matching with truly huge (ascii) files
On Wed, Feb 22, 2012 at 04:44:57PM +1100, Elaina Ann Hyde wrote: So, Python question of the day: I have 2 files that I could normally just read in with asciitable, The first file is a 12 column 8000 row table that I have read in via asciitable and manipulated. The second file is enormous, has over 50,000 rows and about 20 columns. What I want to do is find the best match for (file 1 column 1 and 2) with (file 2 column 4 and 5), return all rows that match from the huge file, join them togeather and save the whole mess as a file with 8000 rows (assuming the smaller table finds one match per row) and 32=12+20 columns. I don't know much about asciitable, so I'm going to have to guess what some of your code does. I think the critical part is where you grab a column from each file: Radeg=dat['ra-drad']*180./math.pi Decdeg=dat['dec-drad']*180./math.pi Radeg2=dat2['ra-drad']*180./math.pi Decdeg2=dat2['dec-drad']*180./math.pi and then compare them, element by element: for i in xrange(len(Radeg)): for j in xrange(len(Radeg2)): #select the value if it is very, very, very close ... The selection criteria is messy and complicated. Start by cleaning it up: elegant code is easier to work with. The first step is to operate on items in the columns directly, rather than indirectly via an index value. Instead of writing your for-loops like this: for i in xrange(len(column)): do something with column[i] do another thing with column[i] Python can iterate over the values in the column directly: for x in column: do something with x do another thing with x You don't save any lines, but you gain a lot of clarity without the unnecessary indirection. Disclaimer: I have never used asciitable, and it is possible that asciitable's column type does not support this. If not, that's pretty awful design! But you can rescue the situation by manually assigning to a variable inside the loop: for i in xrange(len(column)): x = column[i] do something with x do another thing with x If you need the index as well, use the enumerate function: for i, x in enumerate(column): ... Using that form, if column = [1.1, 2.2, 3.3, ...] then (i, x) will take the values (0, 1.1), (1, 2.2), (2, 3.3) ... However, in your case, you have not one column but two. This is where the zip function comes to the rescue, it lines the columns up like teeth in a zipper: delta = 0.01 for i, (a, b) in enumerate(zip(Radeg, Decdeg)): for j, (c, d) in enumerate(zip(Radeg2, Decdeg2)): if i == j: # skip an iteration -- but why continue if a = c+delta and a = c-delta \ and b = d+delta and b = d-delta: write_stuff_to_file(...) Now we can simplify the selection criteria: delta = 0.01 for i, (a, b) in enumerate(zip(Radeg, Decdeg)): for j, (c, d) in enumerate(zip(Radeg2, Decdeg2)): if i == j: # skip an iteration -- but why continue if c-delta = a = c+delta and d-delta = b = d+delta: write_stuff_to_file(...) Already easier to read. (And also likely to be a little faster, although not enough to really make a difference.) Or at least, I find it easier to read, and I hope you do too! You're comparing the (a,b) values from the small file (8,000 rows) with each of the (c,d) values from the large file (50,000 rows). You will have to compare 8000*5=400 million values, which isn't going to be fast in Python unless you can avoid some of those comparisons. If you can assume that there will only be one match per row, then once you have found that match, you can skip to the next iteration of the outer loop by breaking out of the inner loop, and avoid 42,000+ comparisons per row! If you can do this, that will be a BIG saving. delta = 0.01 for i, (a, b) in enumerate(zip(Radeg, Decdeg)): for j, (c, d) in enumerate(zip(Radeg2, Decdeg2)): if i == j: # skip an iteration -- but why continue if c-delta = a = c+delta and d-delta = b = d+delta: write_stuff_to_file(...) # there can only be one match, and we've just found it, # so go on with the next outer loop break But I don't know if that is a safe assumption to make. That depends on the semantics of your data. The next thing to look at is the write_stuff_to_file(...) placeholder, which I'm using to stand in for your code: fopen.write( .join([str(k) for k in list(dat[i])]) + + .join([str(k) for k in list(dat[j])])+\n) and see if that can be improved, but frankly I have to go now, I'll try to come back to that later. P.S. you have: import astropysics Is that module really called astropysics with no H? -- Steven ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Reading/dealing/matching with truly huge (ascii) files
Elaina Ann Hyde wrote:
So, Python question of the day: I have 2 files that I could normally just
read in with asciitable, The first file is a 12 column 8000 row table that
I have read in via asciitable and manipulated. The second file is
enormous, has over 50,000 rows and about 20 columns. What I want to do is
find the best match for (file 1 column 1 and 2) with (file 2 column 4 and
5), return all rows that match from the huge file, join them togeather and
save the whole mess as a file with 8000 rows (assuming the smaller table
finds one match per row) and 32=12+20 columns. So my read code so far is
as follows:
-
import sys
import asciitable
import matplotlib
import scipy
import numpy as np
from numpy import *
import math
import pylab
import random
from pylab import *
import astropysics
import astropysics.obstools
import astropysics.coords
x=small_file
#cannot read blank values (string!) if blank insert -999.99
dat=asciitable.read(x,Reader=asciitable.CommentedHeader,
fill_values=['','-999.99'])
y=large_file
fopen2=open('cfile2match.list','w')
dat2=asciitable.read(y,Reader=asciitable.CommentedHeader,
fill_values=['','-999.99'])
#here are the 2 values for the small file
Radeg=dat['ra-drad']*180./math.pi
Decdeg=dat['dec-drad']*180./math.pi
#here are the 2 values for the large file
Radeg2=dat2['ra-drad']*180./math.pi
Decdeg2=dat2['dec-drad']*180./math.pi
for i in xrange(len(Radeg)):
for j in xrange(len(Radeg2)):
#select the value if it is very, very, very close
if i != j and Radeg[i] = (Radeg2[j]+0.01) and
Radeg[i]
= (Radeg2[j]-0.01) and Decdeg[i] = (Decdeg2[j]+0.01) and
Decdeg[i] = (Decdeg2[j]-0.01):
fopen.write( .join([str(k) for k in
list(dat[i])])+ + .join([str(k) for k in list(dat[j])])+\n)
---
Now this is where I had to stop, this is way, way too long and messy. I
did a similar approach with smaller (9000 lines each) files and it worked
but took awhile, the problem here is I am going to have to play with the
match range to return the best result and give only one (1!) match per row
for my smaller file, i.e. row 1 of small file must match only 1 row of
large file. then I just need to return them both. However, it isn't
clear to me that this is the best way forward. I have been changing the
xrange to low values to play with the matching, but I would appreciate any
ideas. Thanks
If you calculate the distance instead of checking if it's under a certain
threshold you are guaranteed to get (one of the) best matches.
Pseudo-code:
from functools import partial
big_rows = read_big_file_into_memory()
def distance(small_row, big_row):
...
for small_row in read_small_file():
best_match = min(big_rows, key=partial(dist, small_row))
write_to_result_file(best_match)
As to the actual implementation of the distance() function, I don't
understand your problem description (two columns in the first, three in the
second, how does that work), but generally
a, c = extract_columns_from_small_row(small_row)
b, d = extract_columns_from_big_row(big_row)
if (a = b + eps) and (c = d + eps):
# it's good
would typically become
distance(small_row, big_row):
a, c = extract_columns_from_small_row(small_row)
b, d = extract_columns_from_big_row(big_row)
x = a-b
y = c-d
return math.sqrt(x*x+y*y)
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[Tutor] return integer from function
Hi, I have a function that calculates the distance between two points on a sphere. It works but I cant get it to return a float for use in another script. Anyone know how I do that?? The function is below, Thanks, D import math def distance_on_unit_sphere(lat1, long1, lat2, long2): # Convert latitude and longitude to # spherical coordinates in radians. degrees_to_radians = math.pi/180.0 # phi = 90 - latitude phi1 = (90.0 - lat1)*degrees_to_radians phi2 = (90.0 - lat2)*degrees_to_radians # theta = longitude theta1 = long1*degrees_to_radians theta2 = long2*degrees_to_radians # Compute spherical distance from spherical coordinates. # For two locations in spherical coordinates # (1, theta, phi) and (1, theta, phi) # cosine( arc length ) = #sin phi sin phi' cos(theta-theta') + cos phi cos phi' # distance = rho * arc length cos = (math.sin(phi1)*math.sin(phi2)*math.cos(theta1 - theta2) + math.cos(phi1)*math.cos(phi2)) arc = math.acos( cos ) type(arc) arc = arc*6378.1 #print str(arc*6378.1)+' km' # Remember to multiply arc by the radius of the earth # in your favorite set of units to get length. return arc ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] return integer from function
On 22 February 2012 12:57, David Craig dcdavem...@gmail.com wrote: Hi, I have a function that calculates the distance between two points on a sphere. It works but I cant get it to return a float for use in another script. Anyone know how I do that?? snip code cos = (math.sin(phi1)*math.sin(phi2)*math.cos(theta1 - theta2) + math.cos(phi1)*math.cos(phi2)) arc = math.acos( cos ) type(arc) arc = arc*6378.1 #print str(arc*6378.1)+' km' # Remember to multiply arc by the radius of the earth # in your favorite set of units to get length. return arc Hi David, I'm a bit puzzled. A few lines above the return, you have 'type(arc)'. Try replacing that with 'print type(arc)' and also include 'print type(arc)' immediately above your return. I think you will find that the code you posted does return a float. Best, Brian vdB ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
[Tutor] Create a table by writing to a text file.
Hi,
I have created a list of containing strings that represent distances
between many different points and would like to display the results in a
table.
I have been trying to write them to a text file but it is difficult to
organise them into rows and columns with appropriate spacing to make it
readable. I would like something like,
Stations Station1 Station2
Station1 0.033.57654
Station2 33.57654 0.0
but get,
Stations Station1 Station2
Station1 0.0 33.57654
Station2 33.57654 0.0
I've tried adding spaces but to some of the values (i.e. '0.0
') but this is very messy.
Is there a better way to do this?? My code is below.
Thanks
D
# Distance between stations
from dist import dist
import matplotlib.pyplot as plt
import numpy as np
# Guralp GPS decimal coordinates.
# station = [lat, lon, alt]
UFAN = [55.2333142, -7.6770179, 78.3]
UCRUI = [54.9846137, -8.3771698, 75.8]
UGLEN = [54.7064869, -8.7406732, 42.4]
UEASK = [54.2894659, -8.9583439, 9.1]
UACH = [53.8758499, -9.9621948, 22.0]
ULET = [53.5519317, -9.9413447, 70.4]
UHAG = [52.9393892, -9.4344939, 22.7]
ULOOP = [52.5809163, -9.8456417, 10.4]
UBALF = [52.1625237, -10.4099873, 74.3]
ULAMB = [51.7653115, -10.1531573, 13.5]
USHE = [51.5536226, -9.7907148, 115.3]
UGALL = [51.529665, -8.9529546, 33.4]
names = ['UFAN', 'UCRUI', 'UGLEN', 'UEASK', 'UACH', 'ULET', 'UHAG',
'ULOOP', 'UBALF', 'ULAMB', 'USHE', 'UGALL']
stations = [UFAN, UCRUI, UGLEN, UEASK, UACH, ULET, UHAG, ULOOP, UBALF,
ULAMB, USHE, UGALL]
distance = [[]]*len(stations)
for i in range(0,len(stations)):
#distance[i,0] = names[i]
temp = []
for j in range(0,len(stations)):
temp.append('
'+str(dist(stations[i][0],stations[i][1],stations[j][0],stations[j][1])))
distance[i] = temp
testFile = open('testFile.txt', 'a')
testFile.write('Stations ')
for i in range(0,len(stations)):
testFile.write(names[i]+'')
testFile.write('\n')
for i in range(0,len(stations)):
testFile.write(names[i]+' ')
for j in range(0,len(stations)):
testFile.write(distance[i][j]+' ')
testFile.write('\n')
testFile.close()
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Re: [Tutor] Create a table by writing to a text file.
Hi,
I have created a list of containing strings that represent distances between
many different points and would like to display the results in a table.
I have been trying to write them to a text file but it is difficult to
organise them into rows and columns with appropriate spacing to make it
readable. I would like something like,
Stations Station1 Station2
Station1 0.033.57654
Station2 33.57654 0.0
but get,
Stations Station1 Station2
Station1 0.0 33.57654
Station2 33.57654 0.0
I've tried adding spaces but to some of the values (i.e. '0.0')
but this is very messy.
Is there a better way to do this?? My code is below.
This is always a tricky thing to go about. Nicely human-readable doesn't imply
nicely machine readable. Sometimes a single space or a single tab between
values/columns is more practical for a(nother) program to read, but not for
humans.
So I will work from the assummption that you want it human-readable only.
In that case, have a careful read through the string formatting options:
http://docs.python.org/library/stdtypes.html#string-formatting
Before the two tables there, there's a point 4 which mention a minimum field
width; that'd be something you could use. Eg:
print |%20d| % 10
| 10|
print |%20.5f| % 12.3456789
|12.34568|
Hopefully that gets you on the way.
Cheers,
Evert
Thanks
D
# Distance between stations
from dist import dist
import matplotlib.pyplot as plt
import numpy as np
# Guralp GPS decimal coordinates.
# station = [lat, lon, alt]
UFAN = [55.2333142, -7.6770179, 78.3]
UCRUI = [54.9846137, -8.3771698, 75.8]
UGLEN = [54.7064869, -8.7406732, 42.4]
UEASK = [54.2894659, -8.9583439, 9.1]
UACH = [53.8758499, -9.9621948, 22.0]
ULET = [53.5519317, -9.9413447, 70.4]
UHAG = [52.9393892, -9.4344939, 22.7]
ULOOP = [52.5809163, -9.8456417, 10.4]
UBALF = [52.1625237, -10.4099873, 74.3]
ULAMB = [51.7653115, -10.1531573, 13.5]
USHE = [51.5536226, -9.7907148, 115.3]
UGALL = [51.529665, -8.9529546, 33.4]
names = ['UFAN', 'UCRUI', 'UGLEN', 'UEASK', 'UACH', 'ULET', 'UHAG', 'ULOOP',
'UBALF', 'ULAMB', 'USHE', 'UGALL']
stations = [UFAN, UCRUI, UGLEN, UEASK, UACH, ULET, UHAG, ULOOP, UBALF, ULAMB,
USHE, UGALL]
distance = [[]]*len(stations)
for i in range(0,len(stations)):
#distance[i,0] = names[i]
temp = []
for j in range(0,len(stations)):
temp.append('
'+str(dist(stations[i][0],stations[i][1],stations[j][0],stations[j][1])))
distance[i] = temp
testFile = open('testFile.txt', 'a')
testFile.write('Stations ')
for i in range(0,len(stations)):
testFile.write(names[i]+'')
testFile.write('\n')
for i in range(0,len(stations)):
testFile.write(names[i]+' ')
for j in range(0,len(stations)):
testFile.write(distance[i][j]+' ')
testFile.write('\n')
testFile.close()
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Re: [Tutor] Create a table by writing to a text file.
On 22/02/2012 13:40, Evert Rol wrote: Hi, This is always a tricky thing to go about. Nicely human-readable doesn't imply nicely machine readable. Sometimes a single space or a single tab between values/columns is more practical for a(nother) program to read, but not for humans. So I will work from the assummption that you want it human-readable only. In that case, have a careful read through the string formatting options: http://docs.python.org/library/stdtypes.html#string-formatting Before the two tables there, there's a point 4 which mention a minimum field width; that'd be something you could use. Eg: print |%20d| % 10 | 10| print |%20.5f| % 12.3456789 |12.34568| Hopefully that gets you on the way. Cheers, Evert Note that string formatting referenced above is old style, new style can be found here http://docs.python.org/library/string.html#formatexamples -- Cheers. Mark Lawrence. ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Create a table by writing to a text file.
David Craig wrote:
I have been trying to write them to a text file but it is difficult to
organise them into rows and columns with appropriate spacing to make it
readable. I would like something like,
Stations Station1 Station2
Station1 0.033.57654
Station2 33.57654 0.0
[...]
I've tried adding spaces but to some of the values (i.e. '0.0
') but this is very messy.
Try using string formatting strings. E.g.:
print %s %8.2f %8.2f % (station1, 0, 4)
will produce this output:
station1 0.00 4.00
Naturally you don't have to pass the resultant string to print. You can store
it in a variable, and write it to a file:
line = %s %8.2f %8.2f % (station1, 0, 4)
myfile.write(line + '\n')
The format string codes cover a lot of options. Each code starts with a %
sign, and ends with a letter s, d, f, and a few others.
%s string
%d decimal number
%f floating point number
%% use a literal percentage sign
plus others
Inside the format target, you can add optional terms for the field width,
number of decimal points, etc. A few examples:
%8.2f Pad the number to a total width of 8 (or more if necessary),
using two figures after the decimal place. The number is
right-justified and padded on the left with spaces.
%-4.1f Pad the number to a total width of 4 (or more if necessary),
using one figure after the decimal place. The number is
left-justified and padded on the right with spaces.
Lots more options here:
http://docs.python.org/library/stdtypes.html#string-formatting-operations
Alternatively, if you have Python 2.6 or newer, you can use the format method:
print {0} {1:8.2f} {2:8.2f}.format(station1, 0, 4)
will produce this output:
station1 0.00 4.00
See here for more options:
http://docs.python.org/library/string.html#string-formatting
--
Steven
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Re: [Tutor] Create a table by writing to a text file.
David Craig wrote: distance = [[]]*len(stations) That doesn't do what you think it does: a = [[]] * 3 a [[], [], []] a[0].append(42) a [[42], [42], [42]] See? You get a list that contains the same list len(stations) times. Use [[] for _ in stations] instead. ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] return integer from function
David Craig wrote: Hi, I have a function that calculates the distance between two points on a sphere. It works but I cant get it to return a float for use in another script. Anyone know how I do that?? You are going to have to explain what you mean in more detail. If you mean, how can you pass the output of one script as the input of another in the shell, remember that the shell communicates by passing strings through stdout and stdin. So you need to have your first script actually print its output, and then pipe it to the next script, just like you would when using shell commands. On the other hand, if you mean, how do you re-use your distance_on_unit_sphere function in another Python program, you need to import it exactly the same as you import math. For example, if your distance function is in a file sphere.py, and you want to use it in a file calculations.py (say), then put this line at the top of calculations.py: import sphere and now you can use sphere.distance_on_unit_sphere just as you can use math.sin and math.cos. For this to work, though, sphere.py and calculations.py need to be in the same folder. (There are other ways to make that work, but they start getting a little tricky to get right.) On the third hand, if you mean something else, you're going to need to explain what you mean because I have no idea what it might be! :) -- Steven ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Create a table by writing to a text file.
Thanks everyone, was able to get what I wanted from '/t' but I'm sure
the other formatting options will be useful in future.
@Peter
a = [[]] * 3
a
[[], [], []]
a[0].append(42)
a
[[42], [42], [42]]
you had me worried for a minute, but
a = [[]] * 3
a[0]=[1,2,3]
a
[[1, 2, 3], [], []]
On 02/22/2012 01:40 PM, Evert Rol wrote:
Hi,
I have created a list of containing strings that represent distances between
many different points and would like to display the results in a table.
I have been trying to write them to a text file but it is difficult to organise
them into rows and columns with appropriate spacing to make it readable. I
would like something like,
Stations Station1 Station2
Station1 0.033.57654
Station2 33.57654 0.0
but get,
Stations Station1 Station2
Station1 0.0 33.57654
Station2 33.57654 0.0
I've tried adding spaces but to some of the values (i.e. '0.0') but
this is very messy.
Is there a better way to do this?? My code is below.
This is always a tricky thing to go about. Nicely human-readable doesn't imply
nicely machine readable. Sometimes a single space or a single tab between
values/columns is more practical for a(nother) program to read, but not for
humans.
So I will work from the assummption that you want it human-readable only.
In that case, have a careful read through the string formatting options:
http://docs.python.org/library/stdtypes.html#string-formatting
Before the two tables there, there's a point 4 which mention a minimum field
width; that'd be something you could use. Eg:
print |%20d| % 10
| 10|
print |%20.5f| % 12.3456789
|12.34568|
Hopefully that gets you on the way.
Cheers,
Evert
Thanks
D
# Distance between stations
from dist import dist
import matplotlib.pyplot as plt
import numpy as np
# Guralp GPS decimal coordinates.
# station = [lat, lon, alt]
UFAN = [55.2333142, -7.6770179, 78.3]
UCRUI = [54.9846137, -8.3771698, 75.8]
UGLEN = [54.7064869, -8.7406732, 42.4]
UEASK = [54.2894659, -8.9583439, 9.1]
UACH = [53.8758499, -9.9621948, 22.0]
ULET = [53.5519317, -9.9413447, 70.4]
UHAG = [52.9393892, -9.4344939, 22.7]
ULOOP = [52.5809163, -9.8456417, 10.4]
UBALF = [52.1625237, -10.4099873, 74.3]
ULAMB = [51.7653115, -10.1531573, 13.5]
USHE = [51.5536226, -9.7907148, 115.3]
UGALL = [51.529665, -8.9529546, 33.4]
names = ['UFAN', 'UCRUI', 'UGLEN', 'UEASK', 'UACH', 'ULET', 'UHAG', 'ULOOP',
'UBALF', 'ULAMB', 'USHE', 'UGALL']
stations = [UFAN, UCRUI, UGLEN, UEASK, UACH, ULET, UHAG, ULOOP, UBALF, ULAMB,
USHE, UGALL]
distance = [[]]*len(stations)
for i in range(0,len(stations)):
#distance[i,0] = names[i]
temp = []
for j in range(0,len(stations)):
temp.append('
'+str(dist(stations[i][0],stations[i][1],stations[j][0],stations[j][1])))
distance[i] = temp
testFile = open('testFile.txt', 'a')
testFile.write('Stations ')
for i in range(0,len(stations)):
testFile.write(names[i]+'')
testFile.write('\n')
for i in range(0,len(stations)):
testFile.write(names[i]+' ')
for j in range(0,len(stations)):
testFile.write(distance[i][j]+' ')
testFile.write('\n')
testFile.close()
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Re: [Tutor] Create a table by writing to a text file.
On Wed, Feb 22, 2012 at 10:24 AM, David Craig dcdavem...@gmail.com wrote:
you had me worried for a minute, but
a = [[]] * 3
a[0]=[1,2,3]
a
[[1, 2, 3], [], []]
That's not the same thing. In your example you create three copies of the
same empty list inside your outer list. You then throw away the first copy
of the empty list and replace it with a new list. What Peter showed was
mutating that inner list in place. If you aren't really, really careful,
you will eventually get bitten by this if you create your lists with
multiplication.
container = [[]] * 3
You can see that this really is three references to the exact same list:
print [id(item) for item in container]
[17246328, 17246328, 17246328]
If you replace the items, you're fine:
container[0] = [1, 2, 3]
print [id(item) for item in container]
[17245808, 17246328, 17246328]
But as soon as you change the contents of one of those duplicate lists,
you're in trouble:
container[1].append('Data')
print container
[[1, 2, 3], ['Data'], ['Data']]
print [id(item) for item in container]
[17245808, 17246328, 17246328]
--
Jerry
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Re: [Tutor] how to rewrite area.py
On 2/21/2012 6:51 PM, William Stewart wrote: hello I need to rewrite area.py program so that it has separate functions for the perimeter and area of a square, a rectangle, and a circle (3.14 * radius**2). Need to - why? Is this a homework assignment? I am horrible at math and I cannot even figure out what I need to do for this Any help would be appreciated All I have is the menu which looks like this Did you run this program? What results did you get? How did they differ from what you expected? Yes it wont run tdue to some problems in my indents but I am working on it What does being horrible at mat have to do with this? I dont know What do you know about defining functions? Not much Did you write this program yourself? this is new to me it a beginners computer class, but I think this may be too advanced for me , I havent learned anything about python before starting except some basic tutorials If you are taking a Python class and don't know what to do either the class is poorly designed or you are in the wrong class. Please say more about this. We are glad to help, but won't write your homework for you. Someone game me some help but Im not sure if I piut it in right it looks like this import math from math import pi print your options are: print print 1) Area(SQUARE) print 2) Area(RECTANGLE) print 3) Area(CIRCLE) print 4) Perimeter(SQUARE) print 5) Perimeter(RECTANGLE) print 6) Perimeter(CIRCLE) print 7) Exit while True: selection = raw_input(Please select an option from the menu.: ) def get_area_of_square(): print Please enter the width of a square area = width**2 return area def get_area_of_rectangle(): Print please enter the width of a rectangle area = width*height return area def get_radius_of_circle(): print please enter the radius of a circle radius = pi**2 retrun radius SQUARES: area = width*width = width**2 perimeter = width+width+width+width = 4*width RECTANGLES: area = width*height perimeter = width+height+width+height = 2*(width+height) CIRCLES: area = pi*radius**2 circumference = 2*pi*radius thanks ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Create a table by writing to a text file.
On 22/02/12 13:14, David Craig wrote: Hi, I have created a list of containing strings that represent distances between many different points and would like to display the results in a table. Others have mentioned using format strings. If it is only for display you could switch to html. Then defining the table and adding numbers to the cells not only aligns the values but gives you control over colours, borders and fonts. Just another option to consider. -- Alan G Author of the Learn to Program web site http://www.alan-g.me.uk/ ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
[Tutor] Help Designing a simple Program called Life
Hello All, My name is Leo. I'm just beginning to learn python. I am learning on my own and have no previous programming experience. I decided to create a version of john conway's game of life as a personal project. I've been wondering what GUI to use. I've been using Tkinter so far but I've not gotten very far. So far I've started the basic window but now I'm kinda of stuck in how to proceed. My idea is when the program initializes to have a root menu with a series of options. Accepting these options under the new game launches a window where you can set the initial state of the board to the correct dimensions, colors, rules, name and initial distribution of live cells. Accepting that window would launch a window containing the game board and the in-game options. I would like to be able to pause the game, run it at different speeds, and add new live cells to the board. I would like to have multiple boards able to run at once, and I would like the option to save a board and its rules to load at a later time. I'd like any ideas on how to approach this project in general and specific. I'll post the code that I already have later today. ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Help Designing a simple Program called Life
On 2/22/2012 1:50 PM, leo degon wrote: Hello All, My name is Leo. Hi Leo Welcome to Python help. We are a few volunteers who like assisting others. A few guidelines: - always reply-all so a copy goes to the list - reply in-line rather than at the top. - if your code is large put it in a pastebin on the web and post the link. I'm just beginning to learn python. I am learning on my own and have no previous programming experience. I decided to create a version of john conway's game of life as a personal project. I've been wondering what GUI to use. I've been using Tkinter so far but I've not gotten very far. So far I've started the basic window but now I'm kinda of stuck in how to proceed. There are a number of good tutorials on tkinter. Find one and go thru it. My idea is when the program initializes to have a root menu with a series of options. Accepting these options under the new game launches a window where you can set the initial state of the board to the correct dimensions, colors, rules, name and initial distribution of live cells. Accepting that window would launch a window containing the game board and the in-game options. I would like to be able to pause the game, run it at different speeds, and add new live cells to the board. I would like to have multiple boards able to run at once, and I would like the option to save a board and its rules to load at a later time. You have chosen a very ambitious project (for a beginner). I suggest you start by creating one part of the whole - get that working then add one more piece. I'd like any ideas on how to approach this project in general and specific. One idea - start with a fixed dimension grid and one initial state - get the grid to display with the initial state. Then step back, say well done,Leo then add code to advance to subsequent states with some limit. I'll post the code that I already have later today. -- Bob Gailer 919-636-4239 Chapel Hill NC ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Recognizing real numbers
On 2/21/2012 10:00 PM, Michael Lewis wrote:
Hi everyone,
I have some code where I import a file to use a module. That module
that I import
takes text and a multiplier, checks for any numbers in that text and
will then multiply those numbers by the given multiplier. The imported
module is below. I am getting the text from a file that I have which
starts out as:
.5 lb. butter
1.75 Cups Graham Cracker Crumbs
2.0 Cups Powder Sugar
1.0 Cups Peanut Butter
2.0 Cups Semi-sweet Chocolate Chips
It seems that the .isdigit() function that I use doesn't recognize the
.5 as a number and therefore doesn't multiply it. How can I get my
code to recognize numbers such as .5, 1.75 as numbers?
Wow - the requirements just changed. Up tilll now we were dealing with
multiplying each digit. Now we have to parse out a string that
represents a number with decimal places! I hope that we don't raise the
oven temperature in the process.
Is it true that the number to multiply is always at the beginning of a
line? If so that makes the job a lot easier.
Imported module:
def MultiplyText(text, multiplier):
'''Recieve a S int. For digits in S, multiply by multiplier and
return updated S.'''
return ' '.join(str(float(num) * multiplier) if num.isdigit() else
num for num in text)
Module doing the importing/opening/reading/creating a new file
import Homework5_1 as multiply
def DoubleDigits(file_name):
'''Open file/read file/write new file that doubles all int's in the
read file'''
try:
read_file = open(file_name)
except IOError:
return 'No such file.'
new_file_name = file_name + '2'
try:
write_file = open(new_file_name, 'w')
except IOError:
read_file.close()
return 'No such file to write to.'
for line in read_file:
new_line = line.split()
new_line = ''.join(multiply.MultiplyText(new_line, 2))
write_file.write(new_line + '\n')
read_file.close()
write_file.close()
def main():
DoubleDigits(raw_input('What file do you want to open? '))
if '__name__' == '__main__':
print main()
Output that is written to my file:
Peanut Butter Bars
Ingredients
.5 lb. butter
1.75 Cups Graham Cracker Crumbs
4.0 Cups Powder Sugar
2.0 Cups Peanut Butter
4.0 Cups Semi-sweet Chocolate Chips
Melt butter. Add graham cracker crumbs,
peanut butter and sugar. Mix well and
pat into sheet pan. Cover with melted
chocolate. Refrigerate until semi-firm,
then cut into squares.
--
Michael J. Lewis
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919-636-4239
Chapel Hill NC
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[Tutor] I cannot run any Python programs
Hi. I need help. I have installed Python 3.2.2 and have been using IDLE (the Python shell) to type and save a Python program, such as 'Hello World'. However, the command prompt (the black box) will not allow me to type a Python program or to run a Python program. So I tried to run a Python program using Notepad++, and while I am able to type it, I am not able to save it. I am not able to run any Python programs. I have read so much about Python, and have researched the situation in detail, and have experimented with various environmental variables and user/system paths. I need help to correct the situation.. Can someone please help me? Thanks for helping. I look forward to hearing from you. From Your Friend: Tamar Osher Skype: tamarosher Email: emeraldoff...@hotmail.com Message Phone: 011- 1- 513-252-2936 www.HowToBeGifted.com - marketing communication, web design, and much more ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] I cannot run any Python programs
On Wed, Feb 22, 2012 at 5:23 PM, Tamar Osher emeraldoff...@hotmail.com wrote: Hi. I need help. I have installed Python 3.2.2 and have been using IDLE (the Python shell) to type and save a Python program, such as 'Hello World'. However, the command prompt (the black box) will not allow me to type a Python program or to run a Python program. So I tried to run a Python program using Notepad++, and while I am able to type it, I am not able to save it. I am not able to run any Python programs. I have read so much about Python, and have researched the situation in detail, and have experimented with various environmental variables and user/system paths. I need help to correct the situation.. Can someone please help me? Thanks for helping. I look forward to hearing from you. From Your Friend: Tamar Osher Skype: tamarosher Email: emeraldoff...@hotmail.com Message Phone: 011- 1- 513-252-2936 www.HowToBeGifted.com - marketing communication, web design, and much more run cmd to get to the shell. in the shell, navigate to the directory where you have saved your file. type: python myprogram.py Tell us what happens. ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor -- Joel Goldstick ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] I cannot run any Python programs
Dear Joel: HI! Thanks for helping. When I use the Python shell, and navigate to the saved Python program, what happens is: A second Python shell pops up, displaying the coding of the program (which is a tiny 'hello world' program). This is what is displayed in the second Python shell: print(Hello, World!) In the first Python shell, when I type in what you requested, this is what happens: python myprogram.py SyntaxError: invalid syntax python hello.py SyntaxError: invalid syntax I am not able to use the Python shell to find the saved Python program. I am able to use Notepad++ to locate the saved Python program, but I cannot run the program. I cannot do anything with the command prompt (black box). I request help to figure out how to run Python programs. Thanks for helping me! From Your Friend: Tamar Osher Email: emeraldoff...@hotmail.com Date: Wed, 22 Feb 2012 17:33:22 -0500 Subject: Re: [Tutor] I cannot run any Python programs From: joel.goldst...@gmail.com To: emeraldoff...@hotmail.com CC: tutor@python.org On Wed, Feb 22, 2012 at 5:23 PM, Tamar Osher emeraldoff...@hotmail.com wrote: Hi. I need help. I have installed Python 3.2.2 and have been using IDLE (the Python shell) to type and save a Python program, such as 'Hello World'. However, the command prompt (the black box) will not allow me to type a Python program or to run a Python program. So I tried to run a Python program using Notepad++, and while I am able to type it, I am not able to save it. I am not able to run any Python programs. I have read so much about Python, and have researched the situation in detail, and have experimented with various environmental variables and user/system paths. I need help to correct the situation.. Can someone please help me? Thanks for helping. I look forward to hearing from you. From Your Friend: Tamar Osher Skype: tamarosher Email: emeraldoff...@hotmail.com Message Phone: 011- 1- 513-252-2936 www.HowToBeGifted.com - marketing communication, web design, and much more run cmd to get to the shell. in the shell, navigate to the directory where you have saved your file. type: python myprogram.py Tell us what happens. ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor -- Joel Goldstick ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Recognizing real numbers
On 02/21/2012 10:00 PM, Michael Lewis wrote: Hi everyone, I have some code where I import a file to use a module. That module that I import takes text and a multiplier, checks for any numbers in that text and will then multiply those numbers by the given multiplier. The imported module is below. I am getting the text from a file that I have which starts out as: .5 lb. butter 1.75 Cups Graham Cracker Crumbs 2.0 Cups Powder Sugar 1.0 Cups Peanut Butter 2.0 Cups Semi-sweet Chocolate Chips It seems that the .isdigit() function that I use doesn't recognize the .5 as a number and therefore doesn't multiply it. How can I get my code to recognize numbers such as .5, 1.75 as numbers? Imported module: def MultiplyText(text, multiplier): '''Recieve a S int. For digits in S, multiply by multiplier and return updated S.''' return ' '.join(str(float(num) * multiplier) if num.isdigit() else num for num in text) Somehow, every other time I read that code I missed the for num in text phrase that was wrapped around by the mail. I'm apologizing for my earlier remarks stating that this function would not work. i would clean up the variable names (text is a list, and num is a string), and the function comment states that you're multiplying individual digits). But since it works, it's a good base to start with for your floating point question. Easiest answer is to write a function that does check if a string is a valid float, the same as num.isdigit() (lousy names also occur in the standard library) does for int. The new function would be easiest to write with a try/except form. Take a string as a formal parameter, try to float() it in a try block, and if it succeeds, return True. It'd be convenient if there were such a method in str, but since there isn't, you'd have to change num.isdigit() to isfloat(num). Have you gotten to try/except in your class yet? -- DaveA ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Recognizing real numbers
On Wed, Feb 22, 2012 at 4:35 PM, bob gailer bgai...@gmail.com wrote:
On 2/21/2012 10:00 PM, Michael Lewis wrote:
Hi everyone,
I have some code where I import a file to use a module. That module that I
import
takes text and a multiplier, checks for any numbers in that text and will
then multiply those numbers by the given multiplier. The imported module is
below. I am getting the text from a file that I have which starts out as:
.5 lb. butter
1.75 Cups Graham Cracker Crumbs
2.0 Cups Powder Sugar
1.0 Cups Peanut Butter
2.0 Cups Semi-sweet Chocolate Chips
It seems that the .isdigit() function that I use doesn't recognize the .5 as
a number and therefore doesn't multiply it. How can I get my code to
recognize numbers such as .5, 1.75 as numbers?
Wow - the requirements just changed. Up tilll now we were dealing with
multiplying each digit. Now we have to parse out a string that represents a
number with decimal places! I hope that we don't raise the oven temperature
in the process.
Is it true that the number to multiply is always at the beginning of a line?
If so that makes the job a lot easier.
Imported module:
def MultiplyText(text, multiplier):
'''Recieve a S int. For digits in S, multiply by multiplier and return
updated S.'''
return ' '.join(str(float(num) * multiplier) if num.isdigit() else num
for num in text)
Module doing the importing/opening/reading/creating a new file
import Homework5_1 as multiply
def DoubleDigits(file_name):
'''Open file/read file/write new file that doubles all int's in the
read file'''
try:
read_file = open(file_name)
except IOError:
return 'No such file.'
new_file_name = file_name + '2'
try:
write_file = open(new_file_name, 'w')
except IOError:
read_file.close()
return 'No such file to write to.'
for line in read_file:
new_line = line.split()
new_line = ''.join(multiply.MultiplyText(new_line, 2))
write_file.write(new_line + '\n')
read_file.close()
write_file.close()
def main():
DoubleDigits(raw_input('What file do you want to open? '))
if '__name__' == '__main__':
print main()
Output that is written to my file:
Peanut Butter Bars
Ingredients
.5 lb. butter
1.75 Cups Graham Cracker Crumbs
4.0 Cups Powder Sugar
2.0 Cups Peanut Butter
4.0 Cups Semi-sweet Chocolate Chips
Melt butter. Add graham cracker crumbs,
peanut butter and sugar. Mix well and
pat into sheet pan. Cover with melted
chocolate. Refrigerate until semi-firm,
then cut into squares.
--
Michael J. Lewis
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--
Bob Gailer
919-636-4239
Chapel Hill NC
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If the first stuff in the line is always the number, and you capture
the line in s then:
n = float(s.split()[0]) will give you the number. You should wrap
this up with a try block so that it doesn't fail if it isn't a number
split method separates on whitespace and puts each part of the string
in a list. [0] takes the first of those list items. float converts
to a float
--
Joel Goldstick
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Re: [Tutor] I cannot run any Python programs
On Wed, Feb 22, 2012 at 5:49 PM, Tamar Osher emeraldoff...@hotmail.com wrote: Dear Joel: HI! Thanks for helping. When I use the Python shell, and navigate to the saved Python program, what happens is: A second Python shell pops up, displaying the coding of the program (which is a tiny 'hello world' program). This is what is displayed in the second Python shell: print(Hello, World!) In the first Python shell, when I type in what you requested, this is what happens: python myprogram.py SyntaxError: invalid syntax python hello.py SyntaxError: invalid syntax I am not able to use the Python shell to find the saved Python program. I am able to use Notepad++ to locate the saved Python program, but I cannot run the program. I cannot do anything with the command prompt (black box). I request help to figure out how to run Python programs. Thanks for helping me! from the stuff at the start of each line, you are in a python shell. Don't do that. Just get into a command shell. Since I believe you are in windows, press the start button, then run command and the command you run should be cmd This will bring you to a window which looks a lot like DOS used to look. You probably are too young for that. Anyway, at that point, try typing python myprogram.py -- Joel Goldstick ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] I cannot run any Python programs
Dear Joel: Hi! Thanks for helping. I typed cmd, and got the same black box, this time labeled C:\windows\system32\cmd.exe instead of Command Prompt. When I type python myprogram.py, this is what appears on the screen:'python' is not recognized as an internal or external command, operable program, or batch file. Can you help me? I hope so! From Your Friend: Tamar Osher Email: emeraldoff...@hotmail.com Date: Wed, 22 Feb 2012 18:02:23 -0500 Subject: Re: [Tutor] I cannot run any Python programs From: joel.goldst...@gmail.com To: emeraldoff...@hotmail.com CC: tutor@python.org On Wed, Feb 22, 2012 at 5:49 PM, Tamar Osher emeraldoff...@hotmail.com wrote: Dear Joel: HI! Thanks for helping. When I use the Python shell, and navigate to the saved Python program, what happens is: A second Python shell pops up, displaying the coding of the program (which is a tiny 'hello world' program). This is what is displayed in the second Python shell: print(Hello, World!) In the first Python shell, when I type in what you requested, this is what happens: python myprogram.py SyntaxError: invalid syntax python hello.py SyntaxError: invalid syntax I am not able to use the Python shell to find the saved Python program. I am able to use Notepad++ to locate the saved Python program, but I cannot run the program. I cannot do anything with the command prompt (black box). I request help to figure out how to run Python programs. Thanks for helping me! from the stuff at the start of each line, you are in a python shell. Don't do that. Just get into a command shell. Since I believe you are in windows, press the start button, then run command and the command you run should be cmd This will bring you to a window which looks a lot like DOS used to look. You probably are too young for that. Anyway, at that point, try typing python myprogram.py -- Joel Goldstick ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] I cannot run any Python programs
On Wed, Feb 22, 2012 at 6:11 PM, Tamar Osher emeraldoff...@hotmail.com wrote: Dear Joel: Hi! Thanks for helping. I typed cmd, and got the same black box, this time labeled C:\windows\system32\cmd.exe instead of Command Prompt. When I type python myprogram.py, this is what appears on the screen: 'python' is not recognized as an internal or external command, operable program, or batch file. Can you help me? I hope so! From Your Friend: Tamar Osher Email: emeraldoff...@hotmail.com Date: Wed, 22 Feb 2012 18:02:23 -0500 Subject: Re: [Tutor] I cannot run any Python programs From: joel.goldst...@gmail.com To: emeraldoff...@hotmail.com CC: tutor@python.org On Wed, Feb 22, 2012 at 5:49 PM, Tamar Osher emeraldoff...@hotmail.com wrote: Dear Joel: HI! Thanks for helping. When I use the Python shell, and navigate to the saved Python program, what happens is: A second Python shell pops up, displaying the coding of the program (which is a tiny 'hello world' program). This is what is displayed in the second Python shell: print(Hello, World!) In the first Python shell, when I type in what you requested, this is what happens: python myprogram.py SyntaxError: invalid syntax python hello.py SyntaxError: invalid syntax I am not able to use the Python shell to find the saved Python program. I am able to use Notepad++ to locate the saved Python program, but I cannot run the program. I cannot do anything with the command prompt (black box). I request help to figure out how to run Python programs. Thanks for helping me! from the stuff at the start of each line, you are in a python shell. Don't do that. Just get into a command shell. Since I believe you are in windows, press the start button, then run command and the command you run should be cmd This will bring you to a window which looks a lot like DOS used to look. You probably are too young for that. Anyway, at that point, try typing python myprogram.py -- Joel Goldstick Don't top post. Put your comments at the bottom of the message or intersperse where appropriate. I'm not a windows guy anymore. Someone who is can help you figure out how to find out where python is and put it on your path. In the mean time, google microsoft python setting up path and you may be on your way! -- Joel Goldstick ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] I cannot run any Python programs
Thanks! I hope to find a Windows7 expert to help me. ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] how to rewrite area.py
so I copied your format except I changed shape 3 to circle, Did I do the circle part right? and would this be considered seperate functions? Thanks for your help import math from math import pi menu = Pick a shape(1-3): 1) Square 2) Rectangle 3) Triangle 4) Quit shape = int(input(menu)) while shape != 4: if shape == 1: length = float(input(Length: )) print( Area of square = , length ** 2 ) elif shape == 2: length = float(input(Length: )) width = float(input(Width: )) print( Area of rectangle = , length * width ) elif shape == 3: area = float(input(Radius: )) circumference = float(input(radius: )) print( Area of Circle = , pi*radius**2 ) shape = int(input(menu)) OR would this work better? import math from math import pi print your options are: print print 1) Area(SQUARE) print 2) Area(RECTANGLE) print 3) Area(CIRCLE) print 4) Perimeter(SQUARE) print 5) Perimeter(RECTANGLE) print 6) Perimeter(CIRCLE) print 7) Exit while True: selection = raw_input(Please select an option from the menu.: ) def get_area_of_square(): print Please enter the width of a square area = width**2 return area def get_area_of_rectangle(): Print please enter the width of a rectangle area = width*height return area def get_radius_of_circle(): print please enter the radius of a circle radius = pi**2 retrun radius SQUARES: area = width*width = width**2 perimeter = width+width+width+width = 4*width RECTANGLES: area = width*height perimeter = width+height+width+height = 2*(width+height) CIRCLES: area = pi*radius**2 circumference = 2*pi*radius --- On Tue, 2/21/12, Alan Gauld alan.ga...@btinternet.com wrote: From: Alan Gauld alan.ga...@btinternet.com Subject: Re: [Tutor] how to rewrite area.py To: tutor@python.org Date: Tuesday, February 21, 2012, 7:46 PM On 21/02/12 23:51, William Stewart wrote: I need to rewrite area.py program so that it has separate functions for the perimeter and area of a square, a rectangle, and a circle (3.14 * radius**2). You will find something similar in my tutorial in the topic Branching. Look under the heading Python multi-selection and there is some code you should be able to include as template. Have a go and come back with questions. I am horrible at math and I cannot even figure out what I need to do for this Steven has done the math bit for you, so just plug it into the python code you need. -- Alan G Author of the Learn to Program web site http://www.alan-g.me.uk/ ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Help Designing a simple Program called Life
On 22/02/12 18:50, leo degon wrote: Hello All, My name is Leo. I'm just beginning to learn python. I am learning on my own and have no previous programming experience. I decided to create a version of john conway's game of life as a personal project. OK, Thats quite a good project for a beginner because it will require ac number of differentb concepts. I've been wondering what GUI to use. Personally I'd say don't. at least not for a start. Get the game working on the console first then transfer it to the GUI later. One of the fundamental paradigms for GUI program is the Model-View paradigm where you have separate code to represent the logic of the program - the model - from that which displays the UI - The view. You can have different views of the same model. eg. a text view and a graphical view. You can even have both open at the same time! In your case start with a very simple text view using print statements. My idea is when the program initializes to have a root menu with a series of options. In GUI progrqamming beginners often start by thinking about the GUI layout and controls. Thats usually the wrong place to start. Start with the model. In your case that's a grid or matrix with some cells filled in. You need to cyclically recalculate the status of each cell based on the status of the cells around it. (Hint: it may be easier to create a grid thats 1 cell bigger in every direction than your display...) in-game options. I would like to be able to pause the game, run it at different speeds, and add new live cells to the board. I would like to have multiple boards able to run at once, and I would like the option to save a board and its rules to load at a later time. All good ideas but get the most basic one working first a hard coded starting point that morphs into the second generation. Once that works get the cycles running until you hit a key to stop. At that stage we might think about introducing a GUI... But thats probably quie a long way off just yet. I'd like any ideas on how to approach this project in general and specific. Build a little, test a lot. Think about how you will test it before you build it (this is known as test driven development - TDD - in software engineering circles. But it's good for amateurs too!) -- Alan G Author of the Learn to Program web site http://www.alan-g.me.uk/ ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] I cannot run any Python programs
On 22/02/2012 23:29, Tamar Osher wrote: Thanks! I hope to find a Windows7 expert to help me. ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor Try reading this http://docs.python.org/using/windows.html -- Cheers. Mark Lawrence. ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] I cannot run any Python programs
On 22/02/12 23:29, Tamar Osher wrote: Thanks! I hope to find a Windows7 expert to help me. You don't need a Windows 7 expert, just to set things up properly. First open up Notepad++ again and enter everything between the then save to a file called myHello.py and exit Notepad++. print (Hello world, Python calling!) input(Hit return to exit) Find myhello.py in Windows explorer and double click it. (It's probably a good idea to create a special folder to store your python programs. It'll be easier to find them in the future!) If python is installed correctly a black window should open displaying: Hello world, Python calling Hit return to exit If you hit return the window should close. Now open the same file in IDLE (File-Open) You should have a new edit window. In IDLE choose the Run-Run Module menu item. Your program should now run inside IDLE and display its output in the Python Shell window of IDLE. When you hit return this time IDLE stays open but returnms to the Python shell prompt If that all works, great, you are set up. If it doesn't come back and tell us *exactly* what you did and what was displayed. Copy 'n paste any error messages if possible. HTH -- Alan G Author of the Learn to Program web site http://www.alan-g.me.uk/ ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] how to rewrite area.py
On 22/02/12 23:45, William Stewart wrote: so I copied your format except I changed shape 3 to circle, Did I do the circle part right? Nearly. The circumference is wrong, you need to calculate it not read it from the user. and would this be considered separate functions? No, but your second variant is separate functions. You just need to insert them into the first version as appropriate. (After you get them working of course!:-) *elif shape == 3: area = float(input(Radius: )) circumference = float(input(radius: )) print( Area of Circle = , pi*radius**2 ) shape = int(input(menu))* while True: selection = raw_input(Please select an option from the menu.: ) def get_area_of_square(): print Please enter the width of a square This line needs to be an input as you did above. All you are doing here is printing a message not reading anything back. And certainly not assigning anything to width. area = width**2 return area That defines the function but does not call it. You should put the definition outside the loop - above all the code above - and then call it inside the if/else statement: area = get_area_of_square() or even print Area of square = , get_area_of_square() HTH -- Alan G Author of the Learn to Program web site http://www.alan-g.me.uk/ ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
[Tutor] help writing functions
I am learning python and need guidance for writing some code. I've written a simple program (with pointers from people) that parses an tv show xml feed and prints their values in plain text after performing some string operations. [CODE]feed = urllib.urlopen(rssPage) #rssPage: address of xml feed tree = etree.parse(feed) x = tree.xpath(/rss/channel/item/title/text()) x = str(x[0]) for tag in tags: #tags is a list of items like hdtv, xvid, 720p etc x = re.sub(r'\b' + tag + r'\b', '', x) z = re.sub(r'[^\w\s]', '', x) y = tree1.xpath(/rss/channel/item/pubDate/text()) print %s - %s %(z.rstrip(), y[0][:16])[/CODE] The code works fine (prints the name of the show and date). Now since I am parsing more than one feed, I thought the better way was to split the functionality into diff functions: one to get the values and the other to remove the tags. I'm still *very* new to python and came up with the following code. [CODE]def get_value(feed): try: url = urllib2.urlopen(feed) tree = etree.parse(url) x = tree.xpath(/rss/channel/item/title/text()) y = tree.xpath(/rss/channel/item/pubDate/text()) x = str(x[0]) y = str(y[0][:16]) return x return y except SyntaxError: print 'Service Unavailable' pass def del_tag(x): tags = ['HDTV', 'LOL', 'VTV', 'x264', 'DIMENSION', 'XviD', '720P', 'IMMERSE', '720p', 'X264'] for tag in tags: x = re.sub(r'\b' + tag + r'\b', '', x) y = re.sub(r'[^\w\s]', '', x) def main(): a = get_value(rssPage) b = del_tag(a) print b if __name__ == '__main__': main()[/CODE] My desired working is to supply the xml feed address to the [B]get_value[/B] function which returns the title and date as strings assigned to [B]x[/B] and [B]y[/B]. Then I run the [B]del_tag[/B] function on the title string ([B]x[/B]) and remove tags and the [B]main()[/B] function prints both [B]x[/B] and [B]y[/B] (Title, Date). Running this code returns [B]None[/B]. Let the teaching begin :) ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
[Tutor] Which computer operating system is best for Python developers?
Hi. I am still having trouble installing and using Python on my (new) Windows 7 computer, but I plan to contact Microsoft forums and see if they can help me, since this is a Windows problem and not a Python problem. My question: For the future, what type of computer is best for Python developers? Do all Python developers use some type of Unix computer? I appreciate your feedback and look forward to hearing from you. Thanks for your time. From Your Friend: Tamar Osher Email: emeraldoff...@hotmail.com ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Which computer operating system is best for Python developers?
* Tamar Osher emeraldoff...@hotmail.com [2012-02-22 19:00]: Hi. I am still having trouble installing and using Python on my (new) Windows 7 computer, but I plan to contact Microsoft forums and see if they can help me, since this is a Windows problem and not a Python problem. My question: For the future, what type of computer is best for Python developers? Do all Python developers use some type of Unix computer? I appreciate your feedback and look forward to hearing from you. Thanks for your time. As always, the answer is it depends. If you plan on doing Win32 python programming, it doesn't make sense to use anything other than a Windows system. It is usually easier if you can develop on a system that is similar to where your programs will run, but it is by no means a requirement. Your biggest challenge if developing on unlike systems, will be using methods that might be OS-specific (os.fork() comes to mind). As long as you keep things neutral, you shouldn't have huge issues. -- David Rock da...@graniteweb.com pgpOARLwWTZLn.pgp Description: PGP signature ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Which computer operating system is best for Python developers?
On 23/02/2012 01:00, Tamar Osher wrote: Hi. I am still having trouble installing and using Python on my (new) Windows 7 computer, but I plan to contact Microsoft forums and see if they can help me, since this is a Windows problem and not a Python problem. My question: For the future, what type of computer is best for Python developers? Do all Python developers use some type of Unix computer? I appreciate your feedback and look forward to hearing from you. Thanks for your time. From Your Friend: Tamar Osher Email: emeraldoff...@hotmail.com ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor I use Windows simply for the convenience and have never had a problem that couldn't be solved. I guess that some 40 years of industry experience tells me that reading manuals before trying something tends to save time in the long run. -- Cheers. Mark Lawrence. ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Recognizing real numbers (bob gailer)
Hi everyone,
I have some code where I import a file to use a module. That module
that I import
takes text and a multiplier, checks for any numbers in that text and
will then multiply those numbers by the given multiplier. The imported
module is below. I am getting the text from a file that I have which
starts out as:
.5 lb. butter
1.75 Cups Graham Cracker Crumbs
2.0 Cups Powder Sugar
1.0 Cups Peanut Butter
2.0 Cups Semi-sweet Chocolate Chips
It seems that the .isdigit() function that I use doesn't recognize the
.5 as a number and therefore doesn't multiply it. How can I get my
code to recognize numbers such as .5, 1.75 as numbers?
Wow - the requirements just changed. Up tilll now we were dealing with
multiplying each digit. Now we have to parse out a string that
represents a number with decimal places! I hope that we don't raise the
oven temperature in the process.
Well - this is part of my homework and the first question dealt with only
multiplying each digit. the second part of the homework then asked to write
a file that imported the file from the previous homework portion and
utilized the multiplication function in that file. No oven temperature
changes...I promise.
Is it true that the number to multiply is always at the beginning of a
line? If so that makes the job a lot easier.
It's not true. The number can be anywhere in the text.
Imported module:
def MultiplyText(text, multiplier):
'''Recieve a S int. For digits in S, multiply by multiplier and
return updated S.'''
return ' '.join(str(float(num) * multiplier) if num.isdigit() else
num for num in text)
Module doing the importing/opening/reading/creating a new file
import Homework5_1 as multiply
def DoubleDigits(file_name):
'''Open file/read file/write new file that doubles all int's in the
read file'''
try:
read_file = open(file_name)
except IOError:
return 'No such file.'
new_file_name = file_name + '2'
try:
write_file = open(new_file_name, 'w')
except IOError:
read_file.close()
return 'No such file to write to.'
for line in read_file:
new_line = line.split()
new_line = ''.join(multiply.MultiplyText(new_line, 2))
write_file.write(new_line + '\n')
read_file.close()
write_file.close()
def main():
DoubleDigits(raw_input('What file do you want to open? '))
if '__name__' == '__main__':
print main()
Output that is written to my file:
Peanut Butter Bars
Ingredients
.5 lb. butter
1.75 Cups Graham Cracker Crumbs
4.0 Cups Powder Sugar
2.0 Cups Peanut Butter
4.0 Cups Semi-sweet Chocolate Chips
Melt butter. Add graham cracker crumbs,
peanut butter and sugar. Mix well and
pat into sheet pan. Cover with melted
chocolate. Refrigerate until semi-firm,
then cut into squares.
--
Michael J. Lewis
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Re: [Tutor] Recognizing real numbers
On Wed, Feb 22, 2012 at 2:52 PM, Dave Angel d...@davea.name wrote: On 02/21/2012 10:00 PM, Michael Lewis wrote: Hi everyone, I have some code where I import a file to use a module. That module that I import takes text and a multiplier, checks for any numbers in that text and will then multiply those numbers by the given multiplier. The imported module is below. I am getting the text from a file that I have which starts out as: .5 lb. butter 1.75 Cups Graham Cracker Crumbs 2.0 Cups Powder Sugar 1.0 Cups Peanut Butter 2.0 Cups Semi-sweet Chocolate Chips It seems that the .isdigit() function that I use doesn't recognize the .5 as a number and therefore doesn't multiply it. How can I get my code to recognize numbers such as .5, 1.75 as numbers? Imported module: def MultiplyText(text, multiplier): '''Recieve a S int. For digits in S, multiply by multiplier and return updated S.''' return ' '.join(str(float(num) * multiplier) if num.isdigit() else num for num in text) Somehow, every other time I read that code I missed the for num in text phrase that was wrapped around by the mail. No worries - this list has been crazy helpful to me. I'm apologizing for my earlier remarks stating that this function would not work. i would clean up the variable names (text is a list, and num is a string), and the function comment states that you're multiplying individual digits). But since it works, it's a good base to start with for your floating point question. Easiest answer is to write a function that does check if a string is a valid float, the same as num.isdigit() (lousy names also occur in the standard library) does for int. The new function would be easiest to write with a try/except form. Take a string as a formal parameter, try to float() it in a try block, and if it succeeds, return True. It'd be convenient if there were such a method in str, but since there isn't, you'd have to change num.isdigit() to isfloat(num). Have you gotten to try/except in your class yet? We have. I actually have a function written in my imported file to check if a string is a valid float, but I didn't use it because I also have raw_input in that same function, which I don't want. I'll rework the imported function to remove the raw_input and put that in a function by itself so I can utilize the valid float try/except that I've already written. -- DaveA -- Michael J. Lewis mjole...@gmail.com 415.815.7257 ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Reading/dealing/matching with truly huge (ascii) files
On Wed, Feb 22, 2012 at 8:50 PM, Peter Otten __pete...@web.de wrote:
Elaina Ann Hyde wrote:
So, Python question of the day: I have 2 files that I could normally
just
read in with asciitable, The first file is a 12 column 8000 row table
that
I have read in via asciitable and manipulated. The second file is
enormous, has over 50,000 rows and about 20 columns. What I want to do
is
find the best match for (file 1 column 1 and 2) with (file 2 column 4 and
5), return all rows that match from the huge file, join them togeather
and
save the whole mess as a file with 8000 rows (assuming the smaller table
finds one match per row) and 32=12+20 columns. So my read code so far is
as follows:
-
import sys
import asciitable
import matplotlib
import scipy
import numpy as np
from numpy import *
import math
import pylab
import random
from pylab import *
import astropysics
import astropysics.obstools
import astropysics.coords
x=small_file
#cannot read blank values (string!) if blank insert -999.99
dat=asciitable.read(x,Reader=asciitable.CommentedHeader,
fill_values=['','-999.99'])
y=large_file
fopen2=open('cfile2match.list','w')
dat2=asciitable.read(y,Reader=asciitable.CommentedHeader,
fill_values=['','-999.99'])
#here are the 2 values for the small file
Radeg=dat['ra-drad']*180./math.pi
Decdeg=dat['dec-drad']*180./math.pi
#here are the 2 values for the large file
Radeg2=dat2['ra-drad']*180./math.pi
Decdeg2=dat2['dec-drad']*180./math.pi
for i in xrange(len(Radeg)):
for j in xrange(len(Radeg2)):
#select the value if it is very, very, very close
if i != j and Radeg[i] = (Radeg2[j]+0.01) and
Radeg[i]
= (Radeg2[j]-0.01) and Decdeg[i] = (Decdeg2[j]+0.01) and
Decdeg[i] = (Decdeg2[j]-0.01):
fopen.write( .join([str(k) for k in
list(dat[i])])+ + .join([str(k) for k in list(dat[j])])+\n)
---
Now this is where I had to stop, this is way, way too long and messy. I
did a similar approach with smaller (9000 lines each) files and it worked
but took awhile, the problem here is I am going to have to play with the
match range to return the best result and give only one (1!) match per
row
for my smaller file, i.e. row 1 of small file must match only 1 row of
large file. then I just need to return them both. However, it isn't
clear to me that this is the best way forward. I have been changing the
xrange to low values to play with the matching, but I would appreciate
any
ideas. Thanks
If you calculate the distance instead of checking if it's under a certain
threshold you are guaranteed to get (one of the) best matches.
Pseudo-code:
from functools import partial
big_rows = read_big_file_into_memory()
def distance(small_row, big_row):
...
for small_row in read_small_file():
best_match = min(big_rows, key=partial(dist, small_row))
write_to_result_file(best_match)
As to the actual implementation of the distance() function, I don't
understand your problem description (two columns in the first, three in the
second, how does that work), but generally
a, c = extract_columns_from_small_row(small_row)
b, d = extract_columns_from_big_row(big_row)
if (a = b + eps) and (c = d + eps):
# it's good
would typically become
distance(small_row, big_row):
a, c = extract_columns_from_small_row(small_row)
b, d = extract_columns_from_big_row(big_row)
x = a-b
y = c-d
return math.sqrt(x*x+y*y)
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Thanks for all the helpful hints, I really like the idea of using distances
instead of a limit. Walter was right that the 'i !=j' condition was
causing problems. I think that Alan and Steven's use of the index
separately was great as it makes this much easier to test (and yes
'astropysics' is a valid package, it's in there for later when I convert
astrophysical coordinates and whatnot, pretty great but a little buggy
FYI). So I thought, hey, why not try to do a little of all these ideas,
and, if you'll forgive the change in syntax, I think the problem is that
the file might really just be too big to handle, and I'm not sure I have
the right idea with the best_match:
---
#!/usr/bin/python
import sys
import asciitable
import matplotlib
import scipy
import numpy as np
import math
import pylab
import random
from pylab import *
import astropysics
import astropysics.obstools
import astropysics.coords
from astropysics.coords import ICRSCoordinates,GalacticCoordinates
#small
x=open('allfilematch.list')
#really big 2MASS file called 'sgr_2df_big.list'
y=open('/Volumes/Diemos/sgr_2df_big.list')
Re: [Tutor] Recognizing real numbers
On 02/22/2012 08:54 PM, Michael Lewis wrote: On Wed, Feb 22, 2012 at 2:52 PM, Dave Angeld...@davea.name wrote: SNIP I actually have a function written in my imported file to check if a string is a valid float, but I didn't use it because I also have raw_input in that same function, which I don't want. I'll rework the imported function to remove the raw_input and put that in a function by itself so I can utilize the valid float try/except that I've already written. That alone is a valuable lesson. When writing functions, try to make each function do one task, thoroughly and flexibly. Then it's much more likely to be reusable. -- DaveA ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Reading/dealing/matching with truly huge (ascii) files
On 23/02/2012 01:55, Elaina Ann Hyde wrote: [big snips] Hi Elaina, I'm sorry but I can't help with your problem with the memory cos I don't know enough about the combination of Python and Unix wrt memory management. However can I suggest that you use more whitespace in your code to make it easier on all MkI eyeballs, e.g. you have Decdeg2=dat2['col4']+(dat2['col5']/60.)+(dat2['col6']/(60.*60.)) I think this looks better as Decdeg2 = dat2['col4'] + (dat2['col5']/60.) + (dat2['col6'] / (60.*60.)) -- Cheers. Mark Lawrence. ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
[Tutor] Compiled Python File
First, thanks to everyone who helped me out regarding my Recognizing real numbers post. I gained a lot of knowledge over the past two days! I've noticed that after I execute some of my .py files, a Compiled Python File is automatically saved to my directory. This doesn't happen for every file that I execute though. Why is that? Thanks! -- Michael J. Lewis ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Compiled Python File
On Wed, Feb 22, 2012 at 07:29:42PM -0800, Michael Lewis wrote: First, thanks to everyone who helped me out regarding my Recognizing real numbers post. I gained a lot of knowledge over the past two days! I've noticed that after I execute some of my .py files, a Compiled Python File is automatically saved to my directory. This doesn't happen for every file that I execute though. Why is that? When you execute a file directly from the shell, using something like this command: $ python my_python_script.py no .pyc file is created. But when you import a file from within Python, either by hand or within a script: import my_module Python compiles it and saves the compiled version to my_module.pyc so that the next time you call import, it will be faster. -- Steven ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Which computer operating system is best for Python developers?
On Wed, Feb 22, 2012 at 07:00:57PM -0600, Tamar Osher wrote: Hi. I am still having trouble installing and using Python on my (new) Windows 7 computer, but I plan to contact Microsoft forums and see if they can help me, since this is a Windows problem and not a Python problem. My question: For the future, what type of computer is best for Python developers? Do all Python developers use some type of Unix computer? I appreciate your feedback and look forward to hearing from you. Thanks for your time. For sure, Linux is the best OS for development. That doesn't mean that you can't develop on other OSes, or that Linux is perfect, but generally speaking it is the simplest and easiest, at least once you learn the Linux/Unix ways of thinking, or can memorize a few of the most common commands you need to use. And please don't read this as an attack on Windows, or Mac OS, or whatever your favourite OS is. All OSes have their strengths and weaknesses, and the range and quality of free development tools happens to be one of Linux's biggest strength. If you hang around on the python-dev mailing list, you will see that one of Python's ongoing weaknesses is that the developers don't have enough people able and willing to test Python under Windows and fix problems as they occur. When you ask why, they tell you that it's because dealing with Microsoft licencing is difficult, that the C compilers change too often in backwards-incompatible ways, that they can't get people to do testing, that in a thousand little ways it just isn't fun or easy to develop Python on Windows. Or even develop *in* Python. On my Linux system, I get Python pre-installed, plus a whole bunch of programmers' editors, debugging tools, admin tools, etc. If they don't come installed, they are usually one command away: yum install name-of-package aptitude install name-of-package depending on whether you are using Red Hat based Linux, or Debian based Linux. On Windows, every package needs to be installed by hand. If there's a binary installer, I better hope it works on my system, because compiling it myself is a PITA even if I had a C compiler, which I don't. On Windows, I have Notepad, which is a crap editor, WordPad, which isn't designed for programming, or heavyweight IDEs that come with my compiler. I would need to learn a whole new IDE for every language I learn. On Linux, I have half a dozen programmer's editors already available for me. Even the feeblest, nano, is more powerful than Notepad. I just use whatever tools I'm already used to using, and it just works: http://blog.sanctum.geek.nz/series/unix-as-ide/ Unix/Linux is designed to be an development environment, rather than having development be an optional extra. No suprises there: Linux particularly, but also Unix back in the early days, was built by programmers to scratch their own itch: they wanted a good development environment, and so they built Unix to be a good development environment. With Windows and Mac OS, it is primarily designed as a desktop OS, with development being a necessary evil rather than a design choice. If you decide to shift from Windows to something else, you may find that it's more work learning the new OS than it would have been to have just stuck with what you know and learn to use it effectively. -- Steven ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
[Tutor] Writing to a file/changing the file name
Hi everyone,
I have a program where I open a file (recipe.txt), I read that file and
write it to another file. I am doing some multiplying of numbers in
between; however, my question is, when I name the file I am writing to, the
file extension is changed, but the file name is not. What am I doing wrong?
Code:
import Homework5_1 as multiply
def MultiplyNumbersInFile(file_name, multiplier):
'''Open file/read file/write new file that doubles all int's in the
read file'''
try:
read_file = open(file_name)
except IOError:
print I can't find file: , file_name
return
new_file_name = file_name + '2'
try:
write_file = open(new_file_name, 'w')
except IOError:
read_file.close()
print I can't open file: , new_file_name
return
for line in read_file:
new_line = line.split()
new_line = ''.join(multiply.MultiplyText(new_line, multiplier))
write_file.write(new_line + '\n')
read_file.close()
write_file.close()
def main():
file_name = raw_input('What file do you want to open? ')
multiplier = multiply.GetUserNumber()
MultiplyNumbersInFile(file_name, multiplier)
if __name__ == '__main__':
main()
What I am doing in IDLE:
What file do you want to open? recipe.txt
Enter a multiplier: 2
The file that is actually created in my directory is still named recipe;
however, the file type is now TXT2 File. How do I make it so I am updating
the file name to recipe2 instead of the file type?
--
Michael J. Lewis
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Re: [Tutor] Writing to a file/changing the file name
On 2012/02/23 07:04 AM, Michael Lewis wrote:
Hi everyone,
I have a program where I open a file (recipe.txt), I read that file
and write it to another file. I am doing some multiplying of numbers
in between; however, my question is, when I name the file I am writing
to, the file extension is changed, but the file name is not. What am I
doing wrong?
Code:
import Homework5_1 as multiply
def MultiplyNumbersInFile(file_name, multiplier):
'''Open file/read file/write new file that doubles all int's in the
read file'''
try:
read_file = open(file_name)
except IOError:
print I can't find file: , file_name
return
new_file_name = file_name + '2'
try:
write_file = open(new_file_name, 'w')
except IOError:
read_file.close()
print I can't open file: , new_file_name
return
for line in read_file:
new_line = line.split()
new_line = ''.join(multiply.MultiplyText(new_line, multiplier))
write_file.write(new_line + '\n')
read_file.close()
write_file.close()
def main():
file_name = raw_input('What file do you want to open? ')
multiplier = multiply.GetUserNumber()
MultiplyNumbersInFile(file_name, multiplier)
if __name__ == '__main__':
main()
What I am doing in IDLE:
What file do you want to open? recipe.txt
Enter a multiplier: 2
The file that is actually created in my directory is still named
recipe; however, the file type is now TXT2 File. How do I make it so I
am updating the file name to recipe2 instead of the file type?
--
Michael J. Lewis
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That's because your `file_name` variable contains the file name and
extension. You will need to split it into it's component pieces and
then put it back together once you've changed the name, and for that you
can use os.path.splitext
import os
filename, extension = os.path.splitext('recipe.txt')
print (filename, extension)
('recipe', '.txt')
new_filename = filename + '2' + extension
print new_filename
'recipe2.txt'
--
Christian Witts
Python Developer
//
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Re: [Tutor] help writing functions
On 2012-02-23 01:59, Saad Javed wrote: I am learning python and need guidance for writing some code. I've written a simple program (with pointers from people) that parses an tv show xml feed and prints their values in plain text after performing some string operations. [CODE]feed = urllib.urlopen(rssPage) #rssPage: address of xml feed ^^ [snip] Running this code returns [B]None[/B]. ^^^ This is not a web forum, so please post only in plain text. Bye, Andreas ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
