replace_in_file.py

###############################################################################
# Copyright 2014, 2015 IBM Corp.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
###############################################################################
import sys, re
from optparse import OptionParser

usage = "usage: %prog [options] infile outfile"
parser = OptionParser(usage=usage)
parser.add_option("-f", "--from", dest="from_string", type="string",
                  help="The value to that will be replaced.")
parser.add_option("-t", "--to", dest="to_string", type="string",
                  help="The value used to replace the from string.")
parser.add_option("-v", "--verbose", action="store_true", default="false")

(options, args) = parser.parse_args()

if len(args) < 2:
    parser.print_usage()
    exit (-1)

infile = args[0]
outfile = args[1]

if options.verbose:
    print ("infile: %s" %infile)
    print ("outfile: %s" %outfile)
    if options.from_string != None and options.to_string != None:
        print ("Replacing '%s' with '%s'" % (options.from_string, options.to_string))
    elif options.to_string == None:
        print ("No replacement (missing --to argument)")
    elif options.from_string == None:
        print ("No replacement (missing --from argument)")

with open(infile, 'r') as f:
    lines = f.readlines()
    with open(outfile, 'w') as o:
        for line in lines:
            if options.from_string != None and options.to_string != None:
                o.write(re.sub(options.from_string, options.to_string, line))
            else:
                o.write(line)