#!/usr/bin/python3
# written by andrewtunsw.edu.au as a COMP(2041|9044) lecture example

# For each file given as argument replace occurrences of Elizabeth
# and shorter forms of the name  with Darcy and vice-versa.
# Relies on Zaphod not occurring in the text.

# use tempfile to create temporary file - robust & secure

import re, sys, shutil, tempfile

for filename in sys.argv[1:]:
    with tempfile.NamedTemporaryFile(mode="w", delete=False) as tmp:
        with open(filename) as f:
            for line in f:
                changed_line = re.sub(r"Elizabeth|Lizzy|Eliza", "Zaphod", line)
                changed_line = changed_line.replace("Darcy", "Elizabeth")
                changed_line = changed_line.replace("Zaphod", "Darcy")
                tmp.write(changed_line)
    shutil.move(tmp.name, filename)