stablehash

The stablehash module provides a "pure" hash function that is stable across Python processes and runs. This is in contrast to the builtin hash() function, which may return a different value for the same input in separate invokations even with the Python version.

We support most Python built-in types, including mutable types such as list and dict, as well as dataclasses. The default internal hash algorithm is Blake2b, but this can be changed by passing a different hashlib algorithm to the stablehash function.

Usage

from stablehash import stablehash

assert stablehash({"key": "value"}, algorithm="md5").hexdigest() == 'd5994850379366e314563ea555532052'

API

stablehash(obj=..., *, algorithm="blake2b")

Returns a hashlib-compatible object with the given algorithm and the hash of the given object. The algorithm must be one of the algorithms supported by hashlib.

stablehash.update(obj)

Updates the hash with the given object. If the object is not supported, a TypeError is raised.

stablehash.digest()

Returns the digest of the hash as a bytes object.

stablehash.hexdigest()

Returns the digest of the hash as a string object.

Supported types

The following types are supported:

• None
• bool
• int
• float
• str
• bytes
• tuple
• list
• set
• frozenset
• dict
• @dataclass objects
• datetime objects (datetime, date, time and timedelta)
• uuid.UUID
• Picklable objects (e.g. those that implement __getstate__())