flask上下文

import threading
from threading import get_ident

'''
storage = {
	1111:{x1:1}
	1112:{x1:2}
	1113:{x1:3}
	1114:{x1:4}
}
'''

class Local(object):
    def __init__(self):
        object.__setattr__(self, 'storage', {}) # 相当于self.storage = {}
    
    def __setattr__(self, key, value):
        ident = get_ident()
        if ident in self.storage:  # 如果ident在字典里面就直接修改就行了
            self.storage[ident][key] = value
        else: # 不在字典里面就添加
            self.storage[ident] = {key:value}
        
    def __getattr__(self,item):
        ident = get_ident()
        if ident not in self.storage:
            return
        return self.storage[ident].get(item)

local = Local()

def task(num):
    local.x1 = num
    print(local.x1)
    
if __name__ == '__main__':
    for i in range(5):
        t = threading.Thread(target=task, args=(i,))
        t.start()

import threading
from threading import get_ident

'''
storage = {
	1111:{x1:[1]}
	1112:{x1:[]}
	1113:{x1:[]}
	1114:{x1:[]}
}
维护成一个栈
'''

class Local(object):
    def __init__(self):
        object.__setattr__(self, 'storage', {}) # 相当于self.storage = {}
    
    def __setattr__(self, key, value):
        ident = get_ident()
        if ident in self.storage:  # 如果ident在字典里面就直接修改就行了
            self.storage[ident][key].append(value)
        else: # 不在字典里面就添加
            self.storage[ident] = {key:[value]}
        
    def __getattr__(self,item):
        ident = get_ident()
        if ident not in self.storage:
            return
        return self.storage[ident][item][-1]

local = Local()

def task(num):
    local.x1 = num
    print(local.x1)
    
if __name__ == '__main__':
    for i in range(5):
        t = threading.Thread(target=task, args=(i,))
        t.start()

class Local:
    __slots__ = ("_storage",)

    def __init__(self) -> None:
        object.__setattr__(self, "_storage", ContextVar("local_storage"))

    @property
    def __storage__(self) -> t.Dict[str, t.Any]:
        warnings.warn(
            "'__storage__' is deprecated and will be removed in Werkzeug 2.1.",
            DeprecationWarning,
            stacklevel=2,
        )
        return self._storage.get({})  # type: ignore

    @property
    def __ident_func__(self) -> t.Callable[[], int]:
        warnings.warn(
            "'__ident_func__' is deprecated and will be removed in"
            " Werkzeug 2.1. It should not be used in Python 3.7+.",
            DeprecationWarning,
            stacklevel=2,
        )
        return _get_ident  # type: ignore

    @__ident_func__.setter
    def __ident_func__(self, func: t.Callable[[], int]) -> None:
        warnings.warn(
            "'__ident_func__' is deprecated and will be removed in"
            " Werkzeug 2.1. Setting it no longer has any effect.",
            DeprecationWarning,
            stacklevel=2,
        )

    def __release_local__(self) -> None:
        __release_local__(self._storage)

    def __getattr__(self, name: str) -> t.Any:
        values = self._storage.get({})
        try:
            return values[name]
        except KeyError:
            raise AttributeError(name) from None

    def __setattr__(self, name: str, value: t.Any) -> None:
        values = self._storage.get({}).copy()
        values[name] = value
        self._storage.set(values)

    def __delattr__(self, name: str) -> None:
        values = self._storage.get({}).copy()
        try:
            del values[name]
            self._storage.set(values)
        except KeyError:
            raise AttributeError(name) from None

class LocalStack:

    def __init__(self) -> None:
        self._local = Local()

    def __release_local__(self) -> None:
        self._local.__release_local__()

    @property
    def __ident_func__(self) -> t.Callable[[], int]:
        return self._local.__ident_func__

    @__ident_func__.setter
    def __ident_func__(self, value: t.Callable[[], int]) -> None:
        object.__setattr__(self._local, "__ident_func__", value)

    def __call__(self) -> "LocalProxy":
        def _lookup() -> t.Any:
            rv = self.top
            if rv is None:
                raise RuntimeError("object unbound")
            return rv

        return LocalProxy(_lookup)

    def push(self, obj: t.Any) -> t.List[t.Any]:
        """Pushes a new item to the stack"""
        rv = getattr(self._local, "stack", []).copy()
        rv.append(obj)
        self._local.stack = rv
        return rv  # type: ignore

    def pop(self) -> t.Any:
        """Removes the topmost item from the stack, will return the
        old value or `None` if the stack was already empty.
        """
        stack = getattr(self._local, "stack", None)
        if stack is None:
            return None
        elif len(stack) == 1:
            release_local(self._local)
            return stack[-1]
        else:
            return stack.pop()

    @property
    def top(self) -> t.Any:
        """The topmost item on the stack.  If the stack is empty,
        `None` is returned.
        """
        try:
            return self._local.stack[-1]
        except (AttributeError, IndexError):
            return None