python类ref()的实例源码

def __init__(self, weakcontainer):
        # Don't create cycles
        self.weakcontainer = ref(weakcontainer)

def __contains__(self, item):
        return ref(item) in self.data

def add(self, item):
        if self._pending_removals:
            self._commit_removals()
        self.data.add(ref(item, self._remove))

def remove(self, item):
        if self._pending_removals:
            self._commit_removals()
        self.data.remove(ref(item))

def difference_update(self, other):
        if self._pending_removals:
            self._commit_removals()
        if self is other:
            self.data.clear()
        else:
            self.data.difference_update(ref(item) for item in other)

def __isub__(self, other):
        if self._pending_removals:
            self._commit_removals()
        if self is other:
            self.data.clear()
        else:
            self.data.difference_update(ref(item) for item in other)
        return self

def intersection_update(self, other):
        if self._pending_removals:
            self._commit_removals()
        self.data.intersection_update(ref(item) for item in other)

def __iand__(self, other):
        if self._pending_removals:
            self._commit_removals()
        self.data.intersection_update(ref(item) for item in other)
        return self

def issubset(self, other):
        return self.data.issubset(ref(item) for item in other)

def issuperset(self, other):
        return self.data.issuperset(ref(item) for item in other)

def __ge__(self, other):
        return self.data >= set(ref(item) for item in other)

def __eq__(self, other):
        if not isinstance(other, self.__class__):
            return NotImplemented
        return self.data == set(ref(item) for item in other)

def symmetric_difference_update(self, other):
        if self._pending_removals:
            self._commit_removals()
        if self is other:
            self.data.clear()
        else:
            self.data.symmetric_difference_update(ref(item) for item in other)

def __ixor__(self, other):
        if self._pending_removals:
            self._commit_removals()
        if self is other:
            self.data.clear()
        else:
            self.data.symmetric_difference_update(ref(item) for item in other)
        return self

def __init__(self, weakcontainer):
        # Don't create cycles
        self.weakcontainer = ref(weakcontainer)

def __init__(self, data=None):
        self.data = set()
        def _remove(item, selfref=ref(self)):
            self = selfref()
            if self is not None:
                if self._iterating:
                    self._pending_removals.append(item)
                else:
                    self.data.discard(item)
        self._remove = _remove
        # A list of keys to be removed
        self._pending_removals = []
        self._iterating = set()
        if data is not None:
            self.update(data)

def __contains__(self, item):
        try:
            wr = ref(item)
        except TypeError:
            return False
        return wr in self.data

def add(self, item):
        if self._pending_removals:
            self._commit_removals()
        self.data.add(ref(item, self._remove))

def remove(self, item):
        if self._pending_removals:
            self._commit_removals()
        self.data.remove(ref(item))

def __isub__(self, other):
        if self._pending_removals:
            self._commit_removals()
        if self is other:
            self.data.clear()
        else:
            self.data.difference_update(ref(item) for item in other)
        return self