Re: Putting a line from a text file into a variable, then moving to next line

[Jorge Godoy]

Vernon Wenberg III wrote:

 I'm not really sure how readline() works. Is there a way to iterate
 through a file with multiple lines and then putting each line in a
 variable in a loop?

To know how something works you can always check the docs about this
specific functionality:

 a = open('a')
 help(a.readline)
Help on built-in function readline:

readline(...)
readline([size]) - next line from the file, as a string.

Retain newline.  A non-negative size argument limits the maximum
number of bytes to return (an incomplete line may be returned then).
Return an empty string at EOF.

 help(a.readlines)
Help on built-in function readlines:

readlines(...)
readlines([size]) - list of strings, each a line from the file.

Call readline() repeatedly and return a list of the lines so read.
The optional size argument, if given, is an approximate bound on the
total number of bytes in the lines returned.

 


If you are creating new variables on every loop iteration you might be
interested in two things:

- you can loop directly through the file, on a line by line basis
- you can assign the read line to a an array


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Re: Putting a line from a text file into a variable, then moving to next line

[Tim Chase]

 I'm not really sure how readline() works. Is there a way to iterate 
 through a file with multiple lines and then putting each line in a 
 variable in a loop?

You can use readlines() to get the whole line (including the
newline):

  lines = file('x.txt').readlines()

or you can iterate over the file building a list without the newline:

  lines = [line.rstrip('\n') for line in file('x.txt')]

Thus, line[0] will be the first line in your file, line[1] will
be the second, etc.

-tkc




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Re: Putting a line from a text file into a variable, then moving to next line

[Michal Bozon]

On Sun, 07 Oct 2007 12:00:44 +, Vernon Wenberg III wrote:

 I'm not really sure how readline() works. Is there a way to iterate 
 through a file with multiple lines and then putting each line in a 
 variable in a loop?

There are always more ways how to do it.. one of them is:

f = open(filename)
for line in f:
# you may then strip the newline:
line = line.strip('\n')
# do anything you want with the line 
f.close()
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Re: Putting a line from a text file into a variable, then moving to next line

[Tim Williams]

On 07/10/2007, Tim Chase [EMAIL PROTECTED] wrote:
  I'm not really sure how readline() works. Is there a way to iterate
  through a file with multiple lines and then putting each line in a
  variable in a loop?

 You can use readlines() to get the whole line (including the
 newline):

  lines = file('x.txt').readlines()

 or you can iterate over the file building a list without the newline:

  lines = [line.rstrip('\n') for line in file('x.txt')]

 Thus, line[0] will be the first line in your file, line[1] will
 be the second, etc.


or splitlines()
  lines = open('x.txt').read().splitlines()

:)
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