A remix of Bastien Semene code that take Hawkwing comment about generic hashing function into consideration...
def hash_for_file(path, algorithm=hashlib.algorithms[0], block_size=256*128, human_readable=True):
"""
Block size directly depends on the block size of your filesystem
to avoid performances issues
Here I have blocks of 4096 octets (Default NTFS)
Linux Ext4 block size
sudo tune2fs -l /dev/sda5 | grep -i 'block size'
> Block size: 4096
Input:
path: a path
algorithm: an algorithm in hashlib.algorithms
ATM: ('md5', 'sha1', 'sha224', 'sha256', 'sha384', 'sha512')
block_size: a multiple of 128 corresponding to the block size of your filesystem
human_readable: switch between digest() or hexdigest() output, default hexdigest()
Output:
hash
"""
if algorithm not in hashlib.algorithms:
raise NameError('The algorithm "{algorithm}" you specified is '
'not a member of "hashlib.algorithms"'.format(algorithm=algorithm))
hash_algo = hashlib.new(algorithm) # According to hashlib documentation using new()
# will be slower then calling using named
# constructors, ex.: hashlib.md5()
with open(path, 'rb') as f:
for chunk in iter(lambda: f.read(block_size), b''):
hash_algo.update(chunk)
if human_readable:
file_hash = hash_algo.hexdigest()
else:
file_hash = hash_algo.digest()
return file_hash