Usin argparse with stdin and stdout From http://stackoverflow.com/questions/7862987/consistent-way-to-redirect-both-stdin-stdout-to-files-in-python-using-optparse

python_argparse_template.py

#!/usr/bin/env python

import fileinput
import sys
from argparse import ArgumentParser

# https://docs.python.org/dev/library/argparse.html

parser = argparse.ArgumentParser(description = """docstring here""")
parser.add_argument('-i','--input', 
                    help='Input filename', required=True)
parser.add_argument('-o','--output',
                    help='Output filename', required=True)
parser.add_argument('-l','--log',
                    help='Log filename. The default is stdout')
parser.add_argument('-c', '--flag', default= False,
                    help='parameter flag', action='store_true')
args = parser.parse_args()

with open(args.input, 'r') as fh:
    lines = fh.readlines()

if args.log and args.log != '-':
    sys.stdout = open(args.log, 'w')