a = {11,22,33}
#或
a = set() #创建空集合，不能用a={},这样创建的是字典类型

li = [11,22,33,11]
se = set(li)
print(se)  #返回{33, 11, 22}

se1.add(33)  #se1返回{33, 11, 22}，增加元素
se1.clear() #se1返回set()，清空所有元素
se_new = se1.copy() #新集合se_new 返回{11, 22}，浅拷贝

se_new  = se1.difference(se2) #返回新集合，se1中存在但se2中不存在的元素
se1.difference_update(se2) #se1更新为se1中存在且se2中不存在的元素,se1={11}

se_new = se1.symmetric_difference(se2) #对称不同，实际返回两个集合并集去掉两个集合中交集元素，se_new={33, 11, 44}，
实际上是se1中有se2中没有 并集于 se2中有se1中没有的
se1.symmetric_difference_update(se2) #更新对称不同，se1更新为两个集合并集去掉两个集合中交集元素，se1={33, 11, 44}，
实际上是se1中有se2中没有 并集于 se2中有se1中没有的
se_new = se1.intersection(se2) #返回一个新的集合，se_new为两个集合的交集，{22}
se1.intersection_update(se2) #更新se1为se1和se2的交集，se1={22}
se_new = se1.union(se2) #返回新集合，se1与se2的并集
se1.update(se2) #se1更新为，se1与se3的并集，se1={33, 11, 44, 22}
se1.discard(11) #se1={22},抛弃一个元素，如果参数中的元素不存在，不报错
element = se1.pop() #删除任意一个元素，并将删除的元素赋值为element,element=11,se1={22},若果是空集合则抛KeyError异常
se1.remove(11) #从se1中移除11元素，se1 = {22},如果参数在set中不存在这个元素则抛出KeyError异常
bol = se1.isdisjoint(se1) #判断se1与se2是否没有交集，如果没有返回True，如果有返回False,bol=False
bol = se3.issubset(se2) #判断se3是否是子集合，se3的元素完全包含在se2内，则返回True
bol = se2.issuperset(se3) #判断se2是否是父集合，se2的元素完全包含se3,则返回True

class set(object):"""set() -> new empty set objectset(iterable) -> new set objectBuild an unordered collection of unique elements."""def add(self, *args, **kwargs): # real signature unknown"""Add an element to a set.This has no effect if the element is already present.添加一个元素到集合这没有影响如果元素已经存在"""passdef clear(self, *args, **kwargs): # real signature unknown""" Remove all elements from this set. 从这个集合中移除所有元素"""passdef copy(self, *args, **kwargs): # real signature unknown""" Return a shallow copy of a set. 返回一个浅拷贝的集合"""passdef difference(self, *args, **kwargs): # real signature unknown"""Return the difference of two or more sets as a new set.(i.e. all elements that are in this set but not the others.)作为一个新的集合返回两个或多个集合的不同（也就是所有元素在这个集合中，但不在另一个集合中）"""passdef difference_update(self, *args, **kwargs): # real signature unknown""" Remove all elements of another set from this set. 从这个集合中删除另一个集合的所有元素"""passdef discard(self, *args, **kwargs): # real signature unknown"""Remove an element from a set if it is a member.If the element is not a member, do nothing.从一个集合中移除一个元素，如果它是个成员如果这个元素不是一个成员，什么也不做"""passdef intersection(self, *args, **kwargs): # real signature unknown"""Return the intersection of two sets as a new set.(i.e. all elements that are in both sets.)作为一个新的集合返回两个集合的交集（也就是，所有在两个结合中都有对的元素）"""passdef intersection_update(self, *args, **kwargs): # real signature unknown""" Update a set with the intersection of itself and another. 更新一个集合用自己和另一个集合的交集"""passdef isdisjoint(self, *args, **kwargs): # real signature unknown""" Return True if two sets have a null intersection. 返回True 如果两个集合没有交集"""passdef issubset(self, *args, **kwargs): # real signature unknown""" Report whether another set contains this set. 报告是否另一个集合包含这个集合"""passdef issuperset(self, *args, **kwargs): # real signature unknown""" Report whether this set contains another set. 报告是否这个集合包含另一个集合"""passdef pop(self, *args, **kwargs): # real signature unknown"""Remove and return an arbitrary set element.Raises KeyError if the set is empty.移除并返回任意集合元素抛出KeyError 如果集合是空的"""passdef remove(self, *args, **kwargs): # real signature unknown"""Remove an element from a set; it must be a member.If the element is not a member, raise a KeyError.从集合中移除一个元素；它必须是一个成员。如果这个元素不是一个成员，抛出KeyError异常"""passdef symmetric_difference(self, *args, **kwargs): # real signature unknown"""Return the symmetric difference of two sets as a new set.(i.e. all elements that are in exactly one of the sets.)作为一个新的集合返回两个集合的对称不同（也就是所有元素正好在众集合中的一个）实际上是a集合存在且b集合中不存在的元素，并集于，b集合存在且a集合不存在的元素"""passdef symmetric_difference_update(self, *args, **kwargs): # real signature unknown""" Update a set with the symmetric difference of itself and another. 更新一个集合用自己和另一个集合的不同"""passdef union(self, *args, **kwargs): # real signature unknown"""Return the union of sets as a new set.(i.e. all elements that are in either set.)作为一个新的集合返回集合的并集。也就是在这两个集合中的所有元素）"""passdef update(self, *args, **kwargs): # real signature unknown""" Update a set with the union of itself and others. 更新一个集合用自己和另一个集合的并集"""passdef __and__(self, *args, **kwargs): # real signature unknown""" Return self&value. """passdef __contains__(self, y): # real signature unknown; restored from __doc__""" x.__contains__(y) <==> y in x. """passdef __eq__(self, *args, **kwargs): # real signature unknown""" Return self==value. """passdef __getattribute__(self, *args, **kwargs): # real signature unknown""" Return getattr(self, name). """passdef __ge__(self, *args, **kwargs): # real signature unknown""" Return self>=value. """passdef __gt__(self, *args, **kwargs): # real signature unknown""" Return self>value. """passdef __iand__(self, *args, **kwargs): # real signature unknown""" Return self&=value. """passdef __init__(self, seq=()): # known special case of set.__init__"""set() -> new empty set objectset(iterable) -> new set objectBuild an unordered collection of unique elements.# (copied from class doc)"""passdef __ior__(self, *args, **kwargs): # real signature unknown""" Return self|=value. """passdef __isub__(self, *args, **kwargs): # real signature unknown""" Return self-=value. """passdef __iter__(self, *args, **kwargs): # real signature unknown""" Implement iter(self). """passdef __ixor__(self, *args, **kwargs): # real signature unknown""" Return self^=value. """passdef __len__(self, *args, **kwargs): # real signature unknown""" Return len(self). """passdef __le__(self, *args, **kwargs): # real signature unknown""" Return self<=value. """passdef __lt__(self, *args, **kwargs): # real signature unknown""" Return self<value. """pass@staticmethod # known case of __new__def __new__(*args, **kwargs): # real signature unknown""" Create and return a new object.  See help(type) for accurate signature. """passdef __ne__(self, *args, **kwargs): # real signature unknown""" Return self!=value. """passdef __or__(self, *args, **kwargs): # real signature unknown""" Return self|value. """passdef __rand__(self, *args, **kwargs): # real signature unknown""" Return value&self. """passdef __reduce__(self, *args, **kwargs): # real signature unknown""" Return state information for pickling. """passdef __repr__(self, *args, **kwargs): # real signature unknown""" Return repr(self). """passdef __ror__(self, *args, **kwargs): # real signature unknown""" Return value|self. """passdef __rsub__(self, *args, **kwargs): # real signature unknown""" Return value-self. """passdef __rxor__(self, *args, **kwargs): # real signature unknown""" Return value^self. """passdef __sizeof__(self): # real signature unknown; restored from __doc__""" S.__sizeof__() -> size of S in memory, in bytes """passdef __sub__(self, *args, **kwargs): # real signature unknown""" Return self-value. """passdef __xor__(self, *args, **kwargs): # real signature unknown""" Return self^value. """pass__hash__ = None

old_dic = {"#1":11,"#2":22,"#3":33}
new_dic = {"#3":44,"#4":55,"#5":66}old_set = set(old_dic.keys()) #key值转换为集合
new_set = set(new_dic.keys())
set_inter = old_set.intersection(new_set)  #old与new交集
for i in set_inter:  #更新old列表old_dic[i] = new_dic[i]
set_new_dife = new_set.difference(old_set) #new里面存在，old里面不存在的集合
for i in set_new_dife:old_dic[i] = new_dic[i]
set_old_dife = old_set.difference(new_set) #old里面存在，new里面不存在的集合
for i in set_old_dife:old_dic.pop(i)
print(old_dic)