diff.py

#!/usr/bin/env python3

# sys: for reading command-line arguments.
# rich: for coloring the text.
importsys
fromrichimportprint

# Print Usage message if enough arguments are not passed.
iflen(sys.argv) <3:
print("Usage:")
print("\tMust provide two file names as command-line arguments.")
print("\tdiff.py <orignal_file> <changed_file>")
exit(1)

orignal=sys.argv[1]
changed=sys.argv[2]

# Read the contents of the files in lists.
orignal_contents=open(orignal, "r").readlines()
changed_contents=open(changed, "r").readlines()

color="green"
symbol=f"[bold {color}][+]"

print()

# Determine which file has changed much.
iflen(changed_contents) <=len(orignal_contents):
color="red"
symbol=f"[bold {color}][-]"
smallest_sloc, largest_sloc=changed_contents, orignal_contents
else:
smallest_sloc, largest_sloc=orignal_contents, changed_contents

# Go over all the lines to check the changes.
forlineinrange(0, len(smallest_sloc)):
iforignal_contents[line] ==changed_contents[line]:
# Ignore if the lines are same.
continue
else:
# Display the changes on the respective lines of the files.
print(f"[bold red][-] Line {line+1}:[/bold red] {orignal_contents[line]}", end="")
print(f"[bold green][+] Line {line+1}:[/bold green] {changed_contents[line]}")

# Show the additions [+] or deletions [-] for the file that is the largest.
ifline==len(smallest_sloc) -1:
fornew_lineinrange(line+1, len(largest_sloc)):
print(f"{symbol} Line {new_line+1}:[/bold {color}] {largest_sloc[new_line]}")