"""This module contains a code example related to
Think Python, 2nd Edition
by Allen Downey
http://thinkpython2.com
Copyright 2015 Allen Downey
License: http://creativecommons.org/licenses/by/4.0/
"""
from __future__ import print_function, division
def sed(pattern, replace, source, dest):
"""Reads a source file and writes the destination file.
In each line, replaces pattern with replace.
pattern: string
replace: string
source: string filename
dest: string filename
"""
fin = open(source, 'r')
fout = open(dest, 'w')
for line in fin:
line = line.replace(pattern, replace)
fout.write(line)
fin.close()
fout.close()
def main():
pattern = 'pattern'
replace = 'replace'
source = 'sed_tester.txt'
dest = source + '.replaced'
sed(pattern, replace, source, dest)
if __name__ == '__main__':
main()