[Tutor] Python 3 dictionary questions
In playing around with Pyton 3 dictionaries I've come up with 2 questions
1) How are duplicate keys handled? For example:
Qb_Dict = {Montana: [Joe, Montana, 415-123-4567,
joe.mont...@gmail.com,Candlestick Park],
Tarkington: [Fran, 651-321-7657, frank.tarking...@gmail.com,
Metropolitan Stadidum],
Namath: [Joe, 212-222-, joe.nam...@gmail.com, Shea Stadium],
Elway: [John, 303-9876-333, john.el...@gmai.com, Mile High Stadium],
Elway: [Ed, 303-9876-333, john.el...@gmai.com, Mile High
Stadium],
Manning: [Archie,504-888-1234, archie.mann...@gmail.com,
Louisiana Superdome],
Staubach: [Roger,214-765-8989, roger.staub...@gmail.com,
Cowboy Stadium]}
print(Qb_Dict[Elway],\n)# print a dictionary entry
In the above the wrong Elway entry, the second one, where the first
name is Ed, is getting printed. I just added that second Elway row to
see how it would handle duplicates and the results are interesting, to
say the least.
2) Is there a way to print out the actual value of the key, like
Montana would be 0, Tarkington would be 1, etc?
--
Frank L. Cranky Frankie Palmeri
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Re: [Tutor] Python 3 dictionary questions
On 11/23/2011 8:04 AM, Cranky Frankie wrote:
In playing around with Pyton 3 dictionaries I've come up with 2 questions
1) How are duplicate keys handled? For example:
Qb_Dict = {Montana: [Joe, Montana, 415-123-4567,
joe.mont...@gmail.com,Candlestick Park],
Tarkington: [Fran, 651-321-7657, frank.tarking...@gmail.com,
Metropolitan Stadidum],
Namath: [Joe, 212-222-, joe.nam...@gmail.com, Shea Stadium],
Elway: [John, 303-9876-333, john.el...@gmai.com, Mile High Stadium],
Elway: [Ed, 303-9876-333, john.el...@gmai.com, Mile High
Stadium],
Manning: [Archie,504-888-1234, archie.mann...@gmail.com,
Louisiana Superdome],
Staubach: [Roger,214-765-8989, roger.staub...@gmail.com,
Cowboy Stadium]}
print(Qb_Dict[Elway],\n)# print a dictionary entry
In the above the wrong Elway entry, the second one, where the first
name is Ed, is getting printed. I just added that second Elway row to
see how it would handle duplicates and the results are interesting, to
say the least.
Seems like you answered your first question. Dictionaries do not have
duplicate keys. Your 2nd assignment using the key Elway replaced the
first.
2) Is there a way to print out the actual value of the key, like
Montana would be 0, Tarkington would be 1, etc?
Actual value? The actual value of Montana is Montana. Sounds like you
want the index of the entry as though it were in a list. Dictionaries
are not ordered so you can't get that unless you store it as part of the
value.
--
Bob Gailer
919-636-4239
Chapel Hill NC
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Re: [Tutor] Python 3 dictionary questions
On 2011/11/23 03:04 PM, Cranky Frankie wrote:
In playing around with Pyton 3 dictionaries I've come up with 2 questions
1) How are duplicate keys handled? For example:
Qb_Dict = {Montana: [Joe, Montana, 415-123-4567,
joe.mont...@gmail.com,Candlestick Park],
Tarkington: [Fran, 651-321-7657, frank.tarking...@gmail.com,
Metropolitan Stadidum],
Namath: [Joe, 212-222-, joe.nam...@gmail.com, Shea Stadium],
Elway: [John, 303-9876-333, john.el...@gmai.com, Mile High Stadium],
Elway: [Ed, 303-9876-333, john.el...@gmai.com, Mile High
Stadium],
Manning: [Archie,504-888-1234, archie.mann...@gmail.com,
Louisiana Superdome],
Staubach: [Roger,214-765-8989, roger.staub...@gmail.com,
Cowboy Stadium]}
print(Qb_Dict[Elway],\n)# print a dictionary entry
In the above the wrong Elway entry, the second one, where the first
name is Ed, is getting printed. I just added that second Elway row to
see how it would handle duplicates and the results are interesting, to
say the least.
2) Is there a way to print out the actual value of the key, like
Montana would be 0, Tarkington would be 1, etc?
A dictionary is simply a Key:Value store and keys are unique. You're
overwriting your first Elway entry with the second one when it's being
captured. If you want to keep duplicate key values you'll need to
re-look at what data structure you want to use, you can keep using a
dictionary but then you'll need to change the value side of it perhaps
like `{key: {key: value, key: value}}` so you end up with `{'Elway':
{'John': [tel_num, email, home_ground], 'Ed': [tel_num, email,
home_ground]}}` or some other implementation specific to your requirements.
As for your second question, the value of the key is a hash. So to get
the value, you'll need to find what hashing algorithm is used by default
for dictionaries and use that to get the value of it yourself.
--
Christian Witts
Python Developer
//
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Re: [Tutor] Python 3 dictionary questions
On Wed, Nov 23, 2011 at 7:04 AM, Cranky Frankie cranky.fran...@gmail.comwrote:
In playing around with Pyton 3 dictionaries I've come up with 2 questions
1) How are duplicate keys handled? For example:
Qb_Dict = {Montana: [Joe, Montana, 415-123-4567,
joe.mont...@gmail.com,Candlestick Park],
Tarkington: [Fran, 651-321-7657, frank.tarking...@gmail.com,
Metropolitan Stadidum],
Namath: [Joe, 212-222-, joe.nam...@gmail.com, Shea Stadium],
Elway: [John, 303-9876-333, john.el...@gmai.com, Mile High
Stadium],
Elway: [Ed, 303-9876-333, john.el...@gmai.com, Mile High
Stadium],
Manning: [Archie,504-888-1234, archie.mann...@gmail.com,
Louisiana Superdome],
Staubach: [Roger,214-765-8989, roger.staub...@gmail.com,
Cowboy Stadium]}
print(Qb_Dict[Elway],\n)# print a dictionary
entry
In the above the wrong Elway entry, the second one, where the first
name is Ed, is getting printed. I just added that second Elway row to
see how it would handle duplicates and the results are interesting, to
say the least.
2) Is there a way to print out the actual value of the key, like
Montana would be 0, Tarkington would be 1, etc?
I'm not sure about #1, but I can tell you about #2.
Dictionaries are not ordered, so you have absolutely no guarantee which
order they'll appear in when you print them out, or if you iterate over the
dictionary. If you want to maintain some type of order you have a few
options. First, store the keys in a list, which does maintain order:
keys = ['Elway', 'Montana', ... ]
Then you would do something like:
Qb_Dict[keys[0]]
(As a slight aside, I'll direct you to PEP 8 which is the Python style
guide which contains things like naming conventions. If you want your code
to look Pythonic, you should take a look there.)
If you just want them to be sorted, you can run sorted on the keys()
collection from the dictionary:
for key in sorted(Qb_Dict.keys()):
print(Qb_Dict[key])
In Python 3 this will only work if your collection contains comparable
types - if you have {1:'Hello', 'Goodbye':2} then you'll get a TypeError
when it tries to compare 1 and 'Goodbye'
HTH,
Wayne
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Re: [Tutor] Python 3 dictionary questions
Cranky Frankie wrote:
In playing around with Pyton 3 dictionaries I've come up with 2 questions
1) How are duplicate keys handled? For example:
Qb_Dict = {Montana: [Joe, Montana, 415-123-4567,
joe.mont...@gmail.com,Candlestick Park],
Tarkington: [Fran, 651-321-7657, frank.tarking...@gmail.com,
Metropolitan Stadidum],
Namath: [Joe, 212-222-, joe.nam...@gmail.com, Shea Stadium],
Elway: [John, 303-9876-333, john.el...@gmai.com, Mile High
Stadium], Elway: [Ed, 303-9876-333, john.el...@gmai.com, Mile
High Stadium],
Manning: [Archie,504-888-1234, archie.mann...@gmail.com,
Louisiana Superdome],
Staubach: [Roger,214-765-8989, roger.staub...@gmail.com,
Cowboy Stadium]}
print(Qb_Dict[Elway],\n)# print a dictionary
entry
In the above the wrong Elway entry, the second one, where the first
name is Ed, is getting printed. I just added that second Elway row to
see how it would handle duplicates and the results are interesting, to
say the least.
The last one always wins. Perhaps it becomes clearer if you think of
d = {1:1, 1:2}
as syntactic sugar for
d = dict()
d[1] = 1
d[1] = 2
If you want to allow for multiple values per key use a list as the value and
append to that:
d = {}
for k, v in [(1, 1), (2, 2), (1, 3)]:
... d.setdefault(k, []).append(v)
...
d
{1: [1, 3], 2: [2]}
2) Is there a way to print out the actual value of the key, like
Montana would be 0, Tarkington would be 1, etc?
No, the actual key *is* Montana or Tarkington. The dictionary does not
record the insertion order.
There is a collections.OrderedDict, but I recommend that you don't try out
that until you have grokked the builtin dict. As a rule of thumb there are
less usecases for an OrderedDict than you think ;)
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[Tutor] sensing EOF in Python 3.1
I'm reading in a pickled file. The program works but I'm having trouble sensing end of file. Here's the program: # # pickle_in.py # program to read in a pickled file # # Frank L. Palmeri # import pickle # import the pickle module pickle_file = open(d:/Work/pickle_file, rb) # open the pickled input file read_file = pickle.load(pickle_file)# read the first input record new_list=[] # create a new empty list while pickle_file: # loop until end of file for i in range(0, 4): # iterate for each field new_list.append(read_file[i]) # append each field to the new list i = i + 1 # increment loop counter print(new_list) # print the input record from the new list new_list=[] # initialize the new list for the next record read_file = pickle.load(pickle_file)# read the next record in the input file here's the error: Traceback (most recent call last): File D:\MyDocs\Python\pickle_in.py, line 21, in module read_file = pickle.load(pickle_file)# read the next record in the input file File D:\Python31\lib\pickle.py, line 1365, in load encoding=encoding, errors=errors).load() EOFError -- Frank L. Cranky Frankie Palmeri ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
[Tutor] How to shorten this code using classes?
Hi. I have written a simple GUI program. It works just like it is intended to do, but there is a problem, I feel like I could make it shorter. I thought of using classes instead of doing it the way I have done. Here is my code: from tkinter import* button1_color=green button1_value=False button2_color=green button2_value=False class Window(Frame): def __init__(self,master): super (Window,self).__init__(master) self.grid() self.create_widgets() def create_widgets(self): #Creates hello button1 self.hello_bttn1=Button(self,bg=button1_color, text=Hi_1, command=self.button1_clicked) self.hello_bttn1.grid() #Creates hello button2 self.hello_bttn2=Button(self,bg=button2_color, text=Hi_1, command=self.button2_clicked) self.hello_bttn2.grid() def button1_clicked(self): This method runs if button one is clicked def change_button1_value(): global button1_value button1_value=not button1_value change_button1_value() if button1_value: self.hello_bttn1.configure(bg=red, text=Hi_2) def change_button1_color_red(): global button1_color button1_color=(red) change_button1_color_red() else: self.hello_bttn1.configure(bg=green, text=Hi_1) def change_button1_color_green(): global button1_color button1_color=(green) change_button1_color_green() #- def button2_clicked(self): This method runs if button two is clicked def change_button2_value(): global button2_value button2_value=not button2_value change_button2_value() if button2_value: self.hello_bttn2.configure(bg=red, text=Hi_2) def change_button2_color_red(): global button2_color button2_color=(red) change_button2_color_red() else: self.hello_bttn2.configure(text=Hi_1, bg=green) def change_button2_color_green(): global button2_color button2_color=(green) change_button2_color_green() As you can button1_clicked and button2_clicked are very similiar. Imagine that I would use more buttons than just the two that I am using now. It would be a lot of functions then, one for each button. How do I accomplish the same thing as my code does now, but using one function for all buttons instead of one function for each button? Is it possible? I hope these questions aren't stupid. Thank you for your time! Mic root=Tk() root.title(Test) root.geometry(200x200) app=Window(root) root.mainloop() ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] sensing EOF in Python 3.1
Cranky Frankie wrote: I'm reading in a pickled file. The program works but I'm having trouble sensing end of file. Here's the program: # # pickle_in.py # program to read in a pickled file # # Frank L. Palmeri # import pickle # import the pickle module pickle_file = open(d:/Work/pickle_file, rb) # open the pickled input file read_file = pickle.load(pickle_file)# read the first input record new_list=[] # create a new empty list while pickle_file: # loop until end of file for i in range(0, 4): # iterate for each field new_list.append(read_file[i]) # append each field to the new list i = i + 1 # increment loop counter print(new_list) # print the input record from the new list new_list=[] # initialize the new list for the next record read_file = pickle.load(pickle_file)# read the next record in the input file here's the error: Traceback (most recent call last): File D:\MyDocs\Python\pickle_in.py, line 21, in module read_file = pickle.load(pickle_file)# read the next record in the input file File D:\Python31\lib\pickle.py, line 1365, in load encoding=encoding, errors=errors).load() EOFError How did you write the data into the pickle file? The normal approach is to write all your data in one step, e. g. (all code snippets untested) # write list with open(filename, wb) as out: pickle.dump(list_of_records, out) You can then read back all records with # read list with open(filename, rb) as instream: list_of_records = pickle.load(instream) A second approach is also possible, but not appropriate for a newbie: # write list entries with open(filename, wb) as out: for record in list_of_records: pickle.dump(record, out) # read list entries to rebuild the list list_of_records = [] with open(filename, rb) as instream: while True: try: record = pickle.load(instream) except EOFError: break else: list_of_records.append(record) By the way new_list=[] for i in range(0, 4): new_list.append(read_file[i]) i = i + 1 - Here the for-loop is taking care of the value of i, you don't have to increment it manually. - A simpler way to achieve the same is new_list = read_file[:4] ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Physics Engine
I'm more of a beginner, so it would be nice for it to work with Livewires. It doesn't need to be that complex (no need for air pressure, elasticity, or energy.) I just need enough that I will stay on the ground and that when I swing sprites around on a rope, they swing in a circle, not a square. A good reference for making one would be good to. ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] How to shorten this code using classes?
Mic wrote: Hi. I have written a simple GUI program. It works just like it is intended to do, but there is a problem, I feel like I could make it shorter. I thought of using classes instead of doing it the way I have done. Here is my code: from tkinter import* button1_color=green button1_value=False button2_color=green button2_value=False class Window(Frame): def __init__(self,master): super (Window,self).__init__(master) self.grid() self.create_widgets() def create_widgets(self): #Creates hello button1 self.hello_bttn1=Button(self,bg=button1_color, text=Hi_1, command=self.button1_clicked) self.hello_bttn1.grid() #Creates hello button2 self.hello_bttn2=Button(self,bg=button2_color, text=Hi_1, command=self.button2_clicked) self.hello_bttn2.grid() def button1_clicked(self): This method runs if button one is clicked def change_button1_value(): global button1_value button1_value=not button1_value change_button1_value() if button1_value: self.hello_bttn1.configure(bg=red, text=Hi_2) def change_button1_color_red(): global button1_color button1_color=(red) change_button1_color_red() else: self.hello_bttn1.configure(bg=green, text=Hi_1) def change_button1_color_green(): global button1_color button1_color=(green) change_button1_color_green() #- def button2_clicked(self): This method runs if button two is clicked def change_button2_value(): global button2_value button2_value=not button2_value change_button2_value() if button2_value: self.hello_bttn2.configure(bg=red, text=Hi_2) def change_button2_color_red(): global button2_color button2_color=(red) change_button2_color_red() else: self.hello_bttn2.configure(text=Hi_1, bg=green) def change_button2_color_green(): global button2_color button2_color=(green) change_button2_color_green() root=Tk() root.title(Test) root.geometry(200x200) app=Window(root) root.mainloop() As you can button1_clicked and button2_clicked are very similiar. Imagine that I would use more buttons than just the two that I am using now. It would be a lot of functions then, one for each button. How do I accomplish the same thing as my code does now, but using one function for all buttons instead of one function for each button? Is it possible? I chose to ignore the using classes part. If you like you can turn the button_clicked() function into a method of a subclass of Button. You can also move the Button configuration done in create_widgets() into the __init__() method of that subclass. import tkinter as tk from functools import partial def button_clicked(button): if button[bg] == green: button.configure(bg=red, text=Hi 2) else: button.configure(bg=green, text=Hi 1) class Window(tk.Frame): def __init__(self, master): super (Window, self).__init__(master) self.grid() self.create_widgets() def create_widgets(self): for _ in range(2): button = tk.Button(self) command = partial(button_clicked, button) button[command] = command button.grid() command() root = tk.Tk() root.title(Test) root.geometry(200x200) app = Window(root) root.mainloop() ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] How to shorten this code using classes?
On Wed, Nov 23, 2011 at 10:35 AM, Mic o0m...@hotmail.se wrote: Hi. I have written a simple GUI program. It works just like it is intended to do, but there is a problem, I feel like I could make it shorter. I thought of using classes instead of doing it the way I have done. Here is my code: from tkinter import* button1_color=green button1_value=False button2_color=green button2_value=False class Window(Frame): def __init__(self,master): super (Window,self).__init__(master) self.grid() self.create_widgets() def create_widgets(self): #Creates hello button1 self.hello_bttn1=Button(self,**bg=button1_color, text=Hi_1, command=self.button1_clicked) self.hello_bttn1.grid() #Creates hello button2 self.hello_bttn2=Button(self,**bg=button2_color, text=Hi_1, command=self.button2_clicked) self.hello_bttn2.grid() def button1_clicked(self): This method runs if button one is clicked def change_button1_value(): global button1_value button1_value=not button1_value change_button1_value() if button1_value: self.hello_bttn1.configure(bg=**red, text=Hi_2) def change_button1_color_red(): global button1_color button1_color=(red) change_button1_color_red() else: self.hello_bttn1.configure(bg=**green, text=Hi_1) def change_button1_color_green(): global button1_color button1_color=(green) change_button1_color_green() #-** def button2_clicked(self): This method runs if button two is clicked def change_button2_value(): global button2_value button2_value=not button2_value change_button2_value() if button2_value: self.hello_bttn2.configure(bg=**red, text=Hi_2) def change_button2_color_red(): global button2_color button2_color=(red) change_button2_color_red() else: self.hello_bttn2.configure(**text=Hi_1, bg=green) def change_button2_color_green(): global button2_color button2_color=(green) change_button2_color_green() As you can button1_clicked and button2_clicked are very similiar. Imagine that I would use more buttons than just the two that I am using now. It would be a lot of functions then, one for each button. How do I accomplish the same thing as my code does now, but using one function for all buttons instead of one function for each button? Is it possible? I hope these questions aren't stupid. Thank you for your time! Mic root=Tk() root.title(Test) root.geometry(200x200) app=Window(root) root.mainloop() __**_ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/**mailman/listinfo/tutorhttp://mail.python.org/mailman/listinfo/tutor Button 1 and Button 2 already are classes, so unless you need to subclass, you are simply being redundant. A couple things first: don't use globals all over the place unless you want to have a serious headache. You have a wicked about of redundancy in your code, you don't need an object oriented approach to condense, but it can be helpful at times. However, as far as your question. For the two functions, you could subclass Button and add them to your new Button object: (untested) class MyButton(Button): button_color=green button_value=False def __init__(self, *args, **kwargs): super(Button, self).__init__(*args, **kwargs) def change_value_and_color(self): self.button_value = not self.button_value if self.button_value: self.button_color=red self.configure(bg=self.button_color, text=Hi_2) else: self.button_color=green self.hello_bttn1.configure(bg=self.button_value, text=Hi_1) def button_clicked(self): This method runs if button one is clicked self.change_value_and_color() I left in the button_clicked method, but as you can see it is utterly pointless to have it. Just rename your first function and call it directly. ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
[Tutor] sensing EOF in Python 3.1
From: Peter Otten __pete...@web.de wrote:
snip
How did you write the data into the pickle file? The normal approach is to
write all your data in one step, e. g. (all code snippets untested)
Thanks Peter, that was it. I was treating pickle like standard file
i/o when it's not that at all.
The reason why I'm pickling is I'm trying to include information on
Python data structures in the presentaton I'm preparing.
Here are the two programs that now work correctly together:
import pickle
pickle_file = open(d:/Work/pickle_file, wb)
Qb_dict = {Montana: [Joe, Montana, 415-123-4567,
joe.mont...@gmail.com,Candlestick Park],
Tarkington: [Fran, 651-321-7657, frank.tarking...@gmail.com,
Metropolitan Stadidum],
Namath: [Joe, 212-222-, joe.nam...@gmail.com, Shea Stadium],
Elway: [John, 303-9876-333, john.el...@gmai.com, Mile High Stadium],
Elway: [Ed, 303-9876-333, john.el...@gmai.com, Mile High
Stadium],
Manning: [Archie,504-888-1234, archie.mann...@gmail.com,
Louisiana Superdome],
Staubach: [Roger,214-765-8989, roger.staub...@gmail.com,
Cowboy Stadium]}
pickle.dump(Qb_dict, pickle_file)
pickle_file.close()
#
# pickle_in.py
# program to read in a pickled file
#
# Frank L. Palmeri
#
import pickle # import the pickle
module
pickle_file = open(d:/Work/pickle_file, rb) # open the pickled file
read_list = pickle.load(pickle_file)# read the first pickled row
print(read_list)# print the input row from
the pickled file
pickle_file.close() # close the pickled file
--
Frank L. Cranky Frankie Palmeri
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[Tutor] Template class and class design on concrete example xl2csv writer
Hello All,
I have the following code and I am quite satisfied with its design BUT I
have the feeling I can do better.
Basically the, main() execute the program (I did not put the parsing of
arguments function). I am opening
an Excel document and writing content in a CSV one w/ different format.
The design is an abstract template
class XLWriter, and derived 'Xl2Csv', 'Xl2Scsv', 'Xl2text' classes to
write the correct ASCII DOCUMENT to correct format.
The property hook method file_format is implement in these classes and
return an object of type 'XlCsvFileFormat' or 'XlTabFileFormat'.
It allows to put the right file extension and delimiter. These class are
derived from standard csv.excel and csv.excel_tab.
At last a Factory class MakeXlWriter has the job to create the correct
writer.
For now I did not add a strategy pattern which usually goes with the
Template pattern.
Except from that all better design or others critics will be welcome.
Regards
karim
___
from __future__ import print_function
import sys, os, argparse, csv, xlrd
__all__ = ['main', 'Xl2CsvError', 'XLWriter', 'XlCsvFileFormat',
'XlTabFileFormat', 'Xl2Csv', 'Xl2Scsv', 'Xl2text', 'MakeXlWriter']
class Xl2CsvError(Exception):
The exception class to manage the internal program errors.
pass
class XlWriter(object):
Abstract template class.
def __init__(self, xlfilename=None, sheets=None):
Initializer.
if self.__class__.__name__ == 'XlWriter':
raise TypeError('Abstract template Class XlWriter could not
be instanciated directly!')
if not xlfilename:
raise Xl2CsvError('Please provide a non empty file name!')
else:
self._source_name = xlfilename
self._book = xlrd.open_workbook(xlfilename)
if sheets is not None:
if isinstance(sheets[0], int):
self._selected_sheets =
[self._book.sheet_by_index(sheetnum-1) for sheetnum in sheets]
elif isinstance(sheets[0], str):
try:
self._selected_sheets =
[self._book.sheet_by_name(sheetname) for sheetname in sheets]
except xlrd.biffh.XLRDError, e:
print('{0} in file document {1}'.format(e, xlfilename))
sys.exit(1)
else:
raise Xl2CsvError('Sheets element type not recognized!')
else:
self._selected_sheets = self._book.sheets()
def write(self):
The file extraction public method.
for sheet in self._selected_sheets:
xlfilename = '{sheet}{ext}'.format(sheet=sheet.name,
ext='.'+self.file_format.extension.lower())
try:
writer = csv.writer(open(xlfilename, 'wb'),
delimiter=self.file_format.delimiter)
print(Creating csv file '{file}' for sheet '{sheet}'
contained in document {src} format(
sheet=sheet.name, file=xlfilename,
src=self._source_name), end=' ')
for row in xrange(sheet.nrows):
writer.writerow(sheet.row_values(row))
print('Done.')
except csv.Error, e:
print(e)
return 1
return 0
@property
def file_format(self):
Hook method. Need to implement in derived classes.
Should return an XLAsciiFileFormat object to get file extension
and inner delimiter.
pass
class XlCsvFileFormat(csv.excel):
Add file extension to the usual properties of Excel-generated
CSV files.
extension = 'CSV'
class XlTabFileFormat(csv.excel_tab):
Add file extension to the usual properties of Excel-generated
TAB delimited files.
extension = 'TXT'
class Xl2Csv(XlWriter):
@property
def file_format(self):
Hook factory method
return XlCsvFileFormat()
class Xl2Scsv(XlWriter):
@property
def file_format(self):
Hook factory method
_format = XlCsvFileFormat()
_format.extension = 'SCSV'
_format.delimiter = ';'
return _format
class Xl2Text(XlWriter):
@property
def file_format(self):
Hook factory method
return XlTabFileFormat()
class MakeXlWriter(object):
Factory class for XLWriter objects.
@staticmethod
def make(xlfilename=None, sheets=None, extension='CSV'):
if extension == TXT:
return Xl2Text(xlfilename=xlfilename, sheets=sheets)
elif extension == SCSV:
return Xl2Scsv(xlfilename=xlfilename, sheets=sheets)
elif extension == CSV:
return Xl2Csv(xlfilename=xlfilename, sheets=sheets)
def main():
Main of this application
args = _process_command_line()
args.xl.close()
writer = MakeXlWriter.make(xlfilename=args.xl.name,
sheets=args.sheets, extension=args.ext)
return
Re: [Tutor] sensing EOF in Python 3.1
On Wed, Nov 23, 2011 at 12:03 PM, Cranky Frankie
cranky.fran...@gmail.comwrote:
[...]
The reason why I'm pickling is I'm trying to include information on
Python data structures in the presentaton I'm preparing. [...]
In your context why not just use modules?
# data.py
Qb_dict = {Montana: [Joe, Montana, 415-123-4567,
joe.mont...@gmail.com,Candlestick Park],
Tarkington: [Fran, 651-321-7657, frank.tarking...@gmail.com,
Metropolitan Stadidum],
Namath: [Joe, 212-222-, joe.nam...@gmail.com, Shea Stadium],
Elway: [John, 303-9876-333, john.el...@gmai.com, Mile High
Stadium],
Elway: [Ed, 303-9876-333, john.el...@gmai.com, Mile High
Stadium],
Manning: [Archie,504-888-1234, archie.mann...@gmail.com,
Louisiana Superdome],
Staubach: [Roger,214-765-8989, roger.staub...@gmail.com,
Cowboy Stadium]}
# program.py
from data import Qb_dict
print(Qb_dict)
Then you can put whatever comments or data you want. Just make sure that
you don't name your data.py file the same as something built-in. It's
pretty horrible when you try to 'import random' and it doesn't randint() or
anything else that you're looking for.
HTH,
Wayne
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Re: [Tutor] basic class loading question
On 11/22/2011 11:25 AM Cranky Frankie said... snip quarterbacks = [] # Create an empty object list In the interest of preferred techniques, your loop will be more pythonic when you write this part... len_Qb_list = len(Qb_list) # Get the lenght of the list of lists which is the #number of rows in the input data for i in range(0, len_Qb_list): # Iterate for the number of rows nq = Qb(*Qb_list[i])# Create an instance of class Qb called nq #and populate each field quarterbacks.append(nq) # Append an instance of object nq into object list quarterbacks i = i + 1 # Iterate for each row in Qb_list ...like this... for this_qb in Qb_list:# Iterate over Qb_list quarterbacks.append(Qb(*this_qb)) # append Qb instance to quarterbacks ...or even drop the quarterbacks declaration above... quarterbacks = [Qb(*this_qb) for this_qb in Qb_list Emile print (quarterbacks[3].phone) # Print an item from the object list quarterbacks print (Qb_list[3][2]) # Print the same object from the original list of lists ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] How to shorten this code using classes?
I chose to ignore the using classes part. If you like you can turn the button_clicked() function into a method of a subclass of Button. You can also move the Button configuration done in create_widgets() into the __init__() method of that subclass. import tkinter as tk from functools import partial def button_clicked(button): if button[bg] == green: button.configure(bg=red, text=Hi 2) else: button.configure(bg=green, text=Hi 1) class Window(tk.Frame): def __init__(self, master): super (Window, self).__init__(master) self.grid() self.create_widgets() def create_widgets(self): for _ in range(2): button = tk.Button(self) command = partial(button_clicked, button) button[command] = command button.grid() command() root = tk.Tk() root.title(Test) root.geometry(200x200) app = Window(root) root.mainloop() ___ A very elegant solution. Much better than my previous one. However, I am a bit unfamiliar with your way of coding, I assume you are used to a version other than Python 3.2? Because, never before have I seen either of those import tkinter as tk from functools import partial I also wonder, if I implement your solution, is there anyway I can place the buttons in the program as I would like, or will they be played in a straight, vertical row always? Also, assume that I have a already have a window with a button in it. If you press this button, this window is supposed to open. So, if I press the button, will this window open? Because I created the previous window using from tkinter import* and not import tkinter as tk. I hope my English is understandable, because it is not my primary language. Thanks for your help, it is greatly appreciated! ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] sensing EOF in Python 3.1
Cranky Frankie wrote: I'm reading in a pickled file. The program works but I'm having trouble sensing end of file. Here's the program: [...] Traceback (most recent call last): File D:\MyDocs\Python\pickle_in.py, line 21, in module read_file = pickle.load(pickle_file)# read the next record in the input file File D:\Python31\lib\pickle.py, line 1365, in load encoding=encoding, errors=errors).load() EOFError Seems to me that you have successfully found the end of file. I'm not be facetious here. Easier to ask forgiveness afterwards than permission before hand is generally (but not necessarily always) the preferred way of coding things in Python. So instead of trying to predict the end of file ahead of time: while some_hard_to_calculate_condition(): do_stuff_with_pickle() you can catch the error instead: try: while True: # Loop forever, until interrupted do_stuff_with_pickle() except EOFError: # no more pickles, so we must be done pass -- Steven ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] sensing EOF in Python 3.1
Cranky Frankie wrote:
From: Peter Otten __pete...@web.de wrote:
snip
How did you write the data into the pickle file? The normal approach is to
write all your data in one step, e. g. (all code snippets untested)
Thanks Peter, that was it. I was treating pickle like standard file
i/o when it's not that at all.
I don't understand what you mean by this.
Pickle does standard file I/O in the same way that opening a JPEG in an
image view does standard file I/O: both programs read data from a file
the standard, ordinary way, but expect data of a certain format. If you
provide it too little data, you will get an EOF error. If you provide
too much data, or messed up data, then you will some other error. But
the file I/O is exactly the same. It's just that pickle, or your image
viewer, handle it for you.
The reason why I'm pickling is I'm trying to include information on
Python data structures in the presentaton I'm preparing.
Pickling won't tell you anything about Python data structures. Pickling
takes Python data structures, bashes them with a hammer until they stop
wiggling, then runs them through a serialiser turning them into a stream
of text or binary codes.
Pickles tell you only about pickles. You won't learn anything about
(say) dicts by looking at a pickled dict except the bare fact that dicts
can be pickled.
py import pickle
py d = {key: value, another key: 42}
py pickle.dumps(d)
(dp0\nS'another key'\np1\nI42\nsS'key'\np2\nS'value'\np3\ns.
I don't know what you expect to learn about dicts from that.
Here are the two programs that now work correctly together:
import pickle
pickle_file = open(d:/Work/pickle_file, wb)
Qb_dict = { ... contents of dict skipped ... }
pickle.dump(Qb_dict, pickle_file)
pickle_file.close()
Take note that you are pickling a dict. This is important later on.
#
# pickle_in.py
# program to read in a pickled file
#
# Frank L. Palmeri
#
import pickle# import the pickle module
Really? Wow! I thought import pickle meant sort the database!!! *wink*
Sarcasm aside, what else could import pickle mean other than import
the pickle module? The comment adds absolutely nothing to the code. At
best it is superfluous. At worst it is harmful, because code and
comments have a regrettable tendency to get out of sync.
Every comment should carry its weight. If the code is particularly
convoluted, you might write comments explaining *how* you do something,
but generally the code speaks for itself regarding the how, so comments
should explain *why* you do something. If a comment doesn't tell you
something that the code doesn't, that you need to know (or at least
should know). Otherwise it should be throw out into the back alley for
the stray cats to eat.
pickle_file = open(d:/Work/pickle_file, rb) # open the pickled file
read_list = pickle.load(pickle_file)# read the first pickled row
And this is what I'm talking about. It does NOT read the first pickled
row. Pickles don't have rows. In this case, you are reading the first
and only pickled object, which happens to be a dict.
print(read_list) # print the input row from the pickled file
pickle_file.close() # close the pickled file
Every comment in your second file is either unnecessary, or wrong. This
is a good example of the need to comment smart rather than comment
hard.
# Bad:
i += 1 # Add one to i.
# Good:
i += 1 # Adjust i for one-based indexing.
--
Steven
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