Search and replace a string in a file as a python one-liner

replace.py

"""

    Search and replace a string in a file as a python one-liner
    @author Thomas Stachl
    @created Mar 12, 2011
    @license Attribution 3.0 Unported (CC BY 3.0)

    This work is licensed under the Creative Commons Attribution 3.0
    Unported License. To view a copy of this license, visit
    http://creativecommons.org/licenses/by/3.0/ or send a letter to
    Creative Commons, 171 Second Street, Suite 300, San Francisco,
    California, 94105, USA.

"""

def replaceInFile(file, pattern, subst):
    open(file, "r+").write(open(file, "r").read().replace(pattern, subst))