This is a pure python keccak implementation that I wrote for educational purposes. It is not optimised, nor especially well documented. But it does pass all the test vectors, and is moderately readable.
It has a hashlib-compatible interface at the top-level.
Both the original Keccak, SHA-3 and SHAKE variants are supported.
>>> import keccak
>>> keccak.Keccak256(b"hello").hexdigest()
'1c8aff950685c2ed4bc3174f3472287b56d9517b9c948127319a09a7a36deac8'
>>> keccak.SHA3_256(b"world").hexdigest()
'420baf620e3fcd9b3715b42b92506e9304d56e02d3a103499a3a292560cb66b2'
>>> keccak.SHAKE_128(b"goodbye").squeeze(12).hex()
'e99444ef1f48fd1d9709479f'Apache 2.0