Source code for netket.utils.partial
# Copyright 2021 The NetKet Authors - All rights reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
import sys
from functools import partial
[docs]
class HashablePartial(partial):
"""
A class behaving like functools.partial, but that retains it's hash
if it's created with a lexically equivalent (the same) function and
with the same partially applied arguments and keywords.
It also stores the computed hash for faster hashing.
"""
# TODO remove when dropping support for Python < 3.10
def __new__(cls, func, *args, **keywords):
# In Python 3.10+ if func is itself a functools.partial instance,
# functools.partial.__new__ would merge the arguments of this HashablePartial
# instance with the arguments of the func
# Pre 3.10 this does not happen, so here we emulate this behaviour recursively
# This is necessary since functools.partial objects do not have a __code__
# property which we use for the hash
# For python 3.10+ we still need to take care of merging with another HashablePartial
while isinstance(
func, partial if sys.version_info < (3, 10) else HashablePartial
):
original_func = func
func = original_func.func
args = original_func.args + args
keywords = {**original_func.keywords, **keywords}
return super().__new__(cls, func, *args, **keywords)
def __init__(self, *args, **kwargs):
self._hash = None
def __eq__(self, other):
return (
type(other) is HashablePartial
and self.func.__code__ == other.func.__code__
and self.args == other.args
and self.keywords == other.keywords
)
def __hash__(self):
if self._hash is None:
self._hash = hash(
(self.func.__code__, self.args, frozenset(self.keywords.items()))
)
return self._hash
def __repr__(self):
return f"<hashable partial {self.func.__name__} with args={self.args} and kwargs={self.keywords}, hash={hash(self)}>"
# jax.tree_util.register_pytree_node(
# HashablePartial,
# lambda partial_: ((), (partial_.func, partial_.args, partial_.keywords)),
# lambda args, _: StaticPartial(args[0], *args[1], **args[2]),
# )