Re: print odd numbers of lines from tekst WITHOUT space between lines

[breamoreboy]

On Saturday, February 18, 2017 at 6:03:37 PM UTC, Wildman wrote:
> On Sat, 18 Feb 2017 09:38:32 -0800, TTaglo wrote:
> 
> > i = 1
> > f = open ('rosalind_ini5(1).txt')
> > for line in f.readlines():
> > if i % 2 == 0:
> > print line
> > i += 1
> > 
> > 
> > How do i get output without breaks between the lines?
> > 
> > Result:
> > 
> > Other things just make you swear and curse
> > 
> > When you're chewing on life's gristle, don't grumble give a whistle
> > 
> > This will help things turn out for the best
> > 
> > Always look on the bright side of life
> 
> In Python 3 you can do this:
> 
> print(line, end="")
> 
> For Python 2 use this:
> 
> import sys
>   .
>   .
>   .
> sys.stdout.write(line)
> 
> Don' forget...
> f.close()
> 
> -- 
>  GNU/Linux user #557453
> The cow died so I don't need your bull!

For Python 2, strictly from memory:-

from __future__ import print_function

print(line, end="")

Kindest regards.

Mark Lawrence.
-- 
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Re: print odd numbers of lines from tekst WITHOUT space between lines

[Peter Otten]

TTaglo wrote:

> i = 1
> f = open ('rosalind_ini5(1).txt')
> for line in f.readlines():
> if i % 2 == 0:
> print line
> i += 1
> 
> 
> How do i get output without breaks between the lines?

I'm late to the show, but here are a few unsolicited remarks to your code.

(1) The best way to open a file is

with open(filename) as f:
# use the file
# at this point the file is closed without the need to invoke 
# f.close() explicitly

(2) The readlines() method reads the complete file into a list. This can 
become a problem if the file is large. It is better to iterate over the file 
directly:

for line in f:
# use the line

(3) If you read the file into a list you can get all odd lines with

for odd_line in f.readlines()[1::2]:
   # use the odd line

(4) If you follow my advice from (2) and want to avoid the in-memory list 
there's an equivalent itertools.islice() function that you can use like 
this:

import itertools
for odd_line in itertools.islice(f, 1, None, 2):
# use the odd line

(5) sys.stdout.write() was already mentioned, but there is also a 
sys.stdout.writelines() meathod which takes a sequence of strings. With that 
your code may become

import itertools
import sys

with open('rosalind_ini5(1).txt') as f:
sys.stdout.writelines(itertools.islice(f, 1, None, 2))


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Re: print odd numbers of lines from tekst WITHOUT space between lines

[TTaglo]

Op zaterdag 18 februari 2017 18:55:46 UTC+1 schreef boB Stepp:
> On Sat, Feb 18, 2017 at 11:38 AM, TTaglo  wrote:
> > i = 1
> > f = open ('rosalind_ini5(1).txt')
> > for line in f.readlines():
> > if i % 2 == 0:
> > print line
> > i += 1
> >
> >
> > How do i get output without breaks between the lines?
> 
> If you use "print line," (Note the trailing comma.), this should
> suppress the line break that the print statement normally inserts.
> 
> Another suggestion might be to use enumerate() instead of using a
> manual counter in your for loop.
> 
> HTH!
> 
> 
> 
> -- 
> boB

thanks for the help ! 
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Re: print odd numbers of lines from tekst WITHOUT space between lines

[TTaglo]

Op zaterdag 18 februari 2017 18:38:43 UTC+1 schreef TTaglo:
> i = 1
> f = open ('rosalind_ini5(1).txt')
> for line in f.readlines():
> if i % 2 == 0:
> print line
> i += 1
> 
> 
> How do i get output without breaks between the lines?
> 
> Result:
> 
> Other things just make you swear and curse
> 
> When you're chewing on life's gristle, don't grumble give a whistle
> 
> This will help things turn out for the best
> 
> Always look on the bright side of life

thank you all!
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Re: print odd numbers of lines from tekst WITHOUT space between lines

[Wildman via Python-list]

On Sat, 18 Feb 2017 09:38:32 -0800, TTaglo wrote:

> i = 1
> f = open ('rosalind_ini5(1).txt')
> for line in f.readlines():
> if i % 2 == 0:
> print line
> i += 1
> 
> 
> How do i get output without breaks between the lines?
> 
> Result:
> 
> Other things just make you swear and curse
> 
> When you're chewing on life's gristle, don't grumble give a whistle
> 
> This will help things turn out for the best
> 
> Always look on the bright side of life

In Python 3 you can do this:

print(line, end="")

For Python 2 use this:

import sys
  .
  .
  .
sys.stdout.write(line)

Don' forget...
f.close()

-- 
 GNU/Linux user #557453
The cow died so I don't need your bull!
-- 
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Re: print odd numbers of lines from tekst WITHOUT space between lines

[alister]

On Sat, 18 Feb 2017 11:55:34 -0600, boB Stepp wrote:

> On Sat, Feb 18, 2017 at 11:38 AM, TTaglo  wrote:
>> i = 1 f = open ('rosalind_ini5(1).txt')
>> for line in f.readlines():
>> if i % 2 == 0:
>> print line
>> i += 1
>>
>>
>> How do i get output without breaks between the lines?
> 
> If you use "print line," (Note the trailing comma.), this should
> suppress the line break that the print statement normally inserts.
> 
> Another suggestion might be to use enumerate() instead of using a manual
> counter in your for loop.
> 
> HTH!

or simply strip the cr/lf of the end of each line



-- 
Smell from unhygenic janitorial staff wrecked the tape heads
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Re: print odd numbers of lines from tekst WITHOUT space between lines

[boB Stepp]

On Sat, Feb 18, 2017 at 11:38 AM, TTaglo  wrote:
> i = 1
> f = open ('rosalind_ini5(1).txt')
> for line in f.readlines():
> if i % 2 == 0:
> print line
> i += 1
>
>
> How do i get output without breaks between the lines?

If you use "print line," (Note the trailing comma.), this should
suppress the line break that the print statement normally inserts.

Another suggestion might be to use enumerate() instead of using a
manual counter in your for loop.

HTH!



-- 
boB
-- 
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print odd numbers of lines from tekst WITHOUT space between lines

[TTaglo]

i = 1
f = open ('rosalind_ini5(1).txt')
for line in f.readlines():
if i % 2 == 0:
print line
i += 1


How do i get output without breaks between the lines?

Result:

Other things just make you swear and curse

When you're chewing on life's gristle, don't grumble give a whistle

This will help things turn out for the best

Always look on the bright side of life
-- 
https://mail.python.org/mailman/listinfo/python-list