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Reading files with Python

Started by Kaize Jul 1, 2004 at 11:26 AM 8 replies 650+ views

Original Post

Jul 1, 2004 at 11:26 AM

I'm pretty new to python. I'm having trouble getting python to read and display what a files says. Like a txt file. Anyone know what I have to type to get python to look for the file, read, and display what the file says? edit: I know how to make python read files, I just want it to display what it says.

Miserable

Jul 1, 2004 at 11:28 AM

myfile = open('bla.txt')for line in myfile:    print line

Kaize

Author

Kaize

Jul 1, 2004 at 11:32 AM

That was fast. ;p
It displays the txt now, but its in double space for some reason. Know how to fix that?

Fruny

203

Fruny

Jul 1, 2004 at 12:01 PM

The newline character at the end of each ... line, is included in the strings you are iterating on. And print itself does print a newline too. So you get two newlines.

Fix: Either remove the newline from the strings as you go:

myfile = open('bla.txt')for line in myfile:    print line[:-1]

Alternatively:

myfile = open('bla.txt')for line in myfile:    print line.rstrip("\r\n")

Or have print not add a newline

myfile = open('bla.txt')for line in myfile:    print line,

Note that you can use file instead of open.

Kaize

Author

Kaize

Jul 1, 2004 at 12:17 PM

Thanks!

civguy

Jul 1, 2004 at 1:26 PM

Or if you don't care about iterating through the lines, just do

print file('bla.txt').read()

bytecoder

Jul 1, 2004 at 1:35 PM

The Python Documentation is the definite resource if you want to know how to do something in Python, and google is the second.
EDIT:
And by the way, I think it's prefered to use list comprehension and such instead of for loops, e.g:

file = open(...)print "".join([line for line in file])

I also recommend Dive Into Python if you already know how to program; it's a great book.

civguy

Jul 1, 2004 at 2:53 PM

Quote:
Original post by bytecoder
And by the way, I think it's prefered to use list comprehension and such instead of for loops

That applies mostly if you want to construct a list with a simple loop. In this case it seems that one just wants to print out stuff, and I don't see list comprehensions that suitable.

Fruny

203

Fruny

Jul 1, 2004 at 3:31 PM

Quote:
Original post by bytecoder
And by the way, I think it's prefered to use list comprehension and such instead of for loops, e.g:
file = open(...)print "".join([line for line in file])

There is no point in constructing a list comprehension : a file is a lazy iterable object. As such, it is designed to allow efficient for loops.

if you want the file as a single string, just do f.read().
If you want a list of strings, just do f.readlines() or even list(f) (build a list from an iterable).

daerid

Jul 1, 2004 at 9:59 PM

God python has got to have one of the most readable and flexible syntaxes on the planet.

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