Python: Hash a file

import hashlib

BLOCKSIZE = 65536  # Divide file into blocks, so we can handle large files.
hash = hashlib.sha1()  # Or use older `hashlib.md5()`.

with open('file.txt', 'rb') as a_file:
    buf = a_file.read(BLOCKSIZE)
    while len(buf) > 0:
        hash.update(buf)
        buf = a_file.read(BLOCKSIZE)

print(hash.hexdigest())

Via pythoncentral.io.