md5sum.py

#!/usr/local/bin/python3
from __future__ import print_function
import hashlib, sys

def compute_checksum(filehandle):
    results = hashlib.md5()
    while True:
        data = filehandle.read(1024*1024) # one mega at a time
        if len(data) == 0:
            break
        results.update(data)
    return results

if __name__ == '__main__':
    args = sys.argv[1:]
    if not args:
        print('Must supply some filenames', file=sys.stderr)
        sys.exit(1)
    for each in args:
        try:
            with open(each, 'rb') as f:
                md5 = compute_checksum(f)
        except EnvironmentError as err:
            print('Error handling %s: %s' % (each, err), file=sys.stderr)
            continue
        print(md5.hexdigest(), '\t', each)