Generate config file from template using Python search and replace.

[Mr Zaug]

I need to generate a config file based on an existing "template" file. I need to replace a set of strings with other strings globally in the generated file.

Here is a snippet of the template file, where CONTENT_PATH and DAMPATH are two "placeholders" or variables. There are several other such placeholders.

      $include "_dispatcher_publish_filters.any"
      /1000 { /type "allow"  /glob "* /CONTENT_PATH/*.html*" }
      /1001 { /type "allow"  /glob "POST /DAMPATH/www/*.html *" }

The script's user will be asked to type in unique values when prompted for DAMPATH or CONTENT_PATH.

Since I know the variables themselves are not going to change (because the contents of the template file don't spontaneously change) should I be using regex to search for them or is there a better way? I was planning on using re.sub but I don't know whether that's the best way. Here's what my script looks like today.

from sys import argv
import re
from os.path import exists

script, template_file = argv
print "Opening the template file..."

in_file = open(template_file)
lines = in_file.readlines()

print "What is the serial number of the site?",
_NNN = raw_input()

print "What is the brand, or product name?",
_BRAND = raw_input()

print "What is the content path?",
_CONTENT_PATH = raw_input()

out_file = open(_nnn + _brand + "_farm.any", 'w')

for line in lines:
   re.sub('NNN', _NNN, line)
   re.sub('BRAND, _BRAND', line)
   re.sub('CONTENT_PATH', _CONTENT_PATH, line)

out_file.close()