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()