cykooz.rehash is a resumable implementation of SHA1 hasher.
Usage example:
from cykooz.rehash import Sha1
hasher = Sha1()
hasher.update(b'x' * 78)
hasher_state = hasher.serialize()
assert len(hasher_state) == 94
hasher.update(b'x' * 41)
assert hasher.hexdigest() == '4300320394f7ee239bcdce7d3b8bcee173a0cd5c'
new_hasher = Sha1.deserialize(hasher_state)
new_hasher.update(b'x' * 41)
assert new_hasher.hexdigest() == '4300320394f7ee239bcdce7d3b8bcee173a0cd5c'