Easiest way to read/write a file's content in Python

Question

In Ruby you can read from a file using s = File.read(filename). The shortest and clearest I know in Python is

with open(filename) as f:
    s =          


        

Answer 1

This isn't Perl; you don't want to force-fit multiple lines worth of code onto a single line. Write a function, then calling the function takes one line of code.

def read_file(fn):
    """
    >>> import os
    >>> fn = "/tmp/testfile.%i" % os.getpid()
    >>> open(fn, "w+").write("testing")
    >>> read_file(fn)
    'testing'
    >>> os.unlink(fn)
    >>> read_file("/nonexistant")
    Traceback (most recent call last):
        ...
    IOError: [Errno 2] No such file or directory: '/nonexistant'
    """
    with open(fn) as f:
        return f.read()

if __name__ == "__main__":
    import doctest
    doctest.testmod()

Answer 2

with open('x.py') as f: s = f.read()

***grins***

Answer 3

Use pathlib.

Python 3.5 and above:

from pathlib import Path
contents = Path(file_path).read_text()

For lower versions of Python use pathlib2:

$ pip install pathlib2

Then

from pathlib2 import Path
contents = Path(file_path).read_text()

Writing is just as easy:

Path(file_path).write_text('my text')

Answer 4

contents = open(filename).read()

Answer 5

This is same as above but does not handle errors:

s = open(filename, 'r').read()

Answer 6

If you're open to using libraries, try installing forked-path (with either easy_install or pip).

Then you can do:

from path import path
s = path(filename).bytes()

This library is fairly new, but it's a fork of a library that's been floating around Python for years and has been used quite a bit. Since I found this library years ago, I very seldom use os.path or open() any more.