python-telegram-bot/telegram/_telegramobject.py
Simon Damberg 28c8c155ce Improve Subscription of TelegramObject (#2719)
Co-authored-by: Hinrich Mahler <22366557+Bibo-Joshi@users.noreply.github.com>
Co-authored-by: Harshil <37377066+harshil21@users.noreply.github.com>
2022-05-06 18:19:13 +02:00

213 lines
7.2 KiB
Python

#!/usr/bin/env python
#
# A library that provides a Python interface to the Telegram Bot API
# Copyright (C) 2015-2022
# Leandro Toledo de Souza <devs@python-telegram-bot.org>
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU Lesser Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU Lesser Public License for more details.
#
# You should have received a copy of the GNU Lesser Public License
# along with this program. If not, see [http://www.gnu.org/licenses/].
"""Base class for Telegram Objects."""
try:
import ujson as json
except ImportError:
import json # type: ignore[no-redef]
from typing import TYPE_CHECKING, List, Optional, Type, TypeVar, Tuple
from telegram._utils.types import JSONDict
from telegram._utils.warnings import warn
if TYPE_CHECKING:
from telegram import Bot
TO = TypeVar('TO', bound='TelegramObject', covariant=True)
class TelegramObject:
"""Base class for most Telegram objects.
Objects of this type are subscriptable with strings, where ``telegram_object[attribute_name]``
is equivalent to ``telegram_object.attribute_name``. If the object does not have an attribute
with the appropriate name, a :exc:`KeyError` will be raised.
.. versionchanged:: 14.0
``telegram_object['from']`` will look up the key ``from_user``. This is to account for
special cases like :attr:`Message.from_user` that deviate from the official Bot API.
"""
# type hints in __new__ are not read by mypy (https://github.com/python/mypy/issues/1021). As a
# workaround we can type hint instance variables in __new__ using a syntax defined in PEP 526 -
# https://www.python.org/dev/peps/pep-0526/#class-and-instance-variable-annotations
if TYPE_CHECKING:
_id_attrs: Tuple[object, ...]
_bot: Optional['Bot']
# Adding slots reduces memory usage & allows for faster attribute access.
# Only instance variables should be added to __slots__.
__slots__ = (
'_id_attrs',
'_bot',
)
# pylint: disable=unused-argument
def __new__(cls, *args: object, **kwargs: object) -> 'TelegramObject':
# We add _id_attrs in __new__ instead of __init__ since we want to add this to the slots
# w/o calling __init__ in all of the subclasses. This is what we also do in BaseFilter.
instance = super().__new__(cls)
instance._id_attrs = ()
instance._bot = None
return instance
def __str__(self) -> str:
return str(self.to_dict())
def __getitem__(self, item: str) -> object:
if item == 'from':
item = 'from_user'
try:
return getattr(self, item)
except AttributeError as exc:
raise KeyError(
f"Objects of type {self.__class__.__name__} don't have an attribute called "
f"`{item}`."
) from exc
@staticmethod
def _parse_data(data: Optional[JSONDict]) -> Optional[JSONDict]:
return None if data is None else data.copy()
@classmethod
def de_json(cls: Type[TO], data: Optional[JSONDict], bot: 'Bot') -> Optional[TO]:
"""Converts JSON data to a Telegram object.
Args:
data (Dict[:obj:`str`, ...]): The JSON data.
bot (:class:`telegram.Bot`): The bot associated with this object.
Returns:
The Telegram object.
"""
data = cls._parse_data(data)
if data is None:
return None
if cls == TelegramObject:
return cls()
return cls(bot=bot, **data)
@classmethod
def de_list(cls: Type[TO], data: Optional[List[JSONDict]], bot: 'Bot') -> List[Optional[TO]]:
"""Converts JSON data to a list of Telegram objects.
Args:
data (Dict[:obj:`str`, ...]): The JSON data.
bot (:class:`telegram.Bot`): The bot associated with these objects.
Returns:
A list of Telegram objects.
"""
if not data:
return []
return [cls.de_json(d, bot) for d in data]
def to_json(self) -> str:
"""Gives a JSON representation of object.
Returns:
:obj:`str`
"""
return json.dumps(self.to_dict())
def to_dict(self) -> JSONDict:
"""Gives representation of object as :obj:`dict`.
Returns:
:obj:`dict`
"""
data = {}
# We want to get all attributes for the class, using self.__slots__ only includes the
# attributes used by that class itself, and not its superclass(es). Hence we get its MRO
# and then get their attributes. The `[:-2]` slice excludes the `object` class & the
# TelegramObject class itself.
attrs = {attr for cls in self.__class__.__mro__[:-2] for attr in cls.__slots__}
for key in attrs:
if key == 'bot' or key.startswith('_'):
continue
value = getattr(self, key, None)
if value is not None:
if hasattr(value, 'to_dict'):
data[key] = value.to_dict()
else:
data[key] = value
if data.get('from_user'):
data['from'] = data.pop('from_user', None)
return data
def get_bot(self) -> 'Bot':
"""Returns the :class:`telegram.Bot` instance associated with this object.
.. seealso:: :meth: `set_bot`
.. versionadded: 14.0
Raises:
RuntimeError: If no :class:`telegram.Bot` instance was set for this object.
"""
if self._bot is None:
raise RuntimeError(
'This object has no bot associated with it. \
Shortcuts cannot be used.'
)
return self._bot
def set_bot(self, bot: Optional['Bot']) -> None:
"""Sets the :class:`telegram.Bot` instance associated with this object.
.. seealso:: :meth: `get_bot`
.. versionadded: 14.0
Arguments:
bot (:class:`telegram.Bot` | :obj:`None`): The bot instance.
"""
self._bot = bot
def __eq__(self, other: object) -> bool:
# pylint: disable=no-member
if isinstance(other, self.__class__):
if self._id_attrs == ():
warn(
f"Objects of type {self.__class__.__name__} can not be meaningfully tested for"
" equivalence.",
stacklevel=2,
)
if other._id_attrs == ():
warn(
f"Objects of type {other.__class__.__name__} can not be meaningfully tested"
" for equivalence.",
stacklevel=2,
)
return self._id_attrs == other._id_attrs
return super().__eq__(other)
def __hash__(self) -> int:
# pylint: disable=no-member
if self._id_attrs:
return hash((self.__class__, self._id_attrs))
return super().__hash__()