hashlib.blake2b() and some other constructors accept the first chunk of data as the "string" keyword argument.

>>> hashlib.blake2b(string=b'')
<_blake2.blake2b object at 0x7f2847a9c430>
>>> hashlib.blake2s(string=b'')
<_blake2.blake2s object at 0x7f28468f6290>
>>> hashlib.sha3_224(string=b'')
<_sha3.sha3_224 object at 0x7f28468f6608>
>>> hashlib.sha3_256(string=b'')
<_sha3.sha3_256 object at 0x7f28468f6290>
>>> hashlib.sha3_384(string=b'')
<_sha3.sha3_384 object at 0x7f28468f6608>
>>> hashlib.sha3_512(string=b'')
<_sha3.sha3_512 object at 0x7f28468f6290>
>>> hashlib.shake_128(string=b'')
<_sha3.shake_128 object at 0x7f28468f6608>
>>> hashlib.shake_256(string=b'')
<_sha3.shake_256 object at 0x7f28468f6290>