team-10/env/Lib/site-packages/streamlit/util.py

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# Copyright (c) Streamlit Inc. (2018-2022) Snowflake Inc. (2022-2025)
#
# 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.
"""A bunch of useful utilities."""
from __future__ import annotations
import dataclasses
import functools
import hashlib
from typing import Any, Callable
def memoize(func: Callable[..., Any]) -> Callable[..., Any]:
"""Decorator to memoize the result of a no-args func."""
result: list[Any] = []
@functools.wraps(func)
def wrapped_func() -> Any:
if not result:
result.append(func())
return result[0]
return wrapped_func
def repr_(self: Any) -> str:
"""A clean repr for a class, excluding both values that are likely defaults,
and those explicitly default for dataclasses.
"""
classname = self.__class__.__name__
# Most of the falsey value, but excluding 0 and 0.0, since those often have
# semantic meaning within streamlit.
defaults: list[Any] = [None, "", False, [], set(), {}]
if dataclasses.is_dataclass(self):
fields_vals = (
(f.name, getattr(self, f.name))
for f in dataclasses.fields(self)
if f.repr
and getattr(self, f.name) != f.default
and getattr(self, f.name) not in defaults
)
else:
fields_vals = ((f, v) for (f, v) in self.__dict__.items() if v not in defaults)
field_reprs = ", ".join(f"{field}={value!r}" for field, value in fields_vals)
return f"{classname}({field_reprs})"
def calc_md5(s: bytes | str) -> str:
"""Return the md5 hash of the given string.
This should not be used for security-related purposes.
"""
# Due to security issue in md5 and sha1, usedforsecurity
h = hashlib.new("md5", usedforsecurity=False)
b = s.encode("utf-8") if isinstance(s, str) else s
h.update(b)
return h.hexdigest()
class AttributeDictionary(dict[Any, Any]):
"""
A dictionary subclass that supports attribute-style access.
This class extends the functionality of a standard dictionary to allow items
to be accessed via attribute-style dot notation in addition to the traditional
key-based access. If a dictionary item is accessed and is itself a dictionary,
it is automatically wrapped in another `AttributeDictionary`, enabling recursive
attribute-style access.
"""
def __getattr__(self, key: str) -> Any:
try:
item = self.__getitem__(key)
return AttributeDictionary(item) if isinstance(item, dict) else item
except KeyError as err:
raise AttributeError(
f"'{type(self).__name__}' object has no attribute '{key}'"
) from err
def __setattr__(self, name: str, value: Any) -> None:
self[name] = value