python __builtins__ frozenset类 （27）

27、'frozenset', 返回一个冻结的集合，冻结后集合不能再添加或删除任何元素。

class frozenset(object)
 |  frozenset() -> empty frozenset object
 |  frozenset(iterable) -> frozenset object
 |  
 |  Build an immutable unordered collection of unique elements.
    # 创建一个不可变得，无序的，元素唯一的集合
 |  
 |  Methods defined here:
 |  
 |  __and__(self, value, /)
 |      Return self&value.
 |  
 |  __contains__(...)
 |      x.__contains__(y) <==> y in x.
 |  
 |  __eq__(self, value, /)
 |      Return self==value.
 |  
 |  __ge__(self, value, /)
 |      Return self>=value.
 |  
 |  __getattribute__(self, name, /)
 |      Return getattr(self, name).
 |  
 |  __gt__(self, value, /)
 |      Return self>value.
 |  
 |  __hash__(self, /)
 |      Return hash(self).
 |  
 |  __iter__(self, /)
 |      Implement iter(self).
 |  
 |  __le__(self, value, /)
 |      Return self<=value.
 |  
 |  __len__(self, /)
 |      Return len(self).
 |  
 |  __lt__(self, value, /)
 |      Return self<value.
 |  
 |  __ne__(self, value, /)
 |      Return self!=value.
 |  
 |  __new__(*args, **kwargs) from builtins.type
 |      Create and return a new object.  See help(type) for accurate signature.
 |  
 |  __or__(self, value, /)
 |      Return self|value.
 |  
 |  __rand__(self, value, /)
 |      Return value&self.
 |  
 |  __reduce__(...)
 |      Return state information for pickling.
 |  
 |  __repr__(self, /)
 |      Return repr(self).
 |  
 |  __ror__(self, value, /)
 |      Return value|self.
 |  
 |  __rsub__(self, value, /)
 |      Return value-self.
 |  
 |  __rxor__(self, value, /)
 |      Return value^self.
 |  
 |  __sizeof__(...)
 |      S.__sizeof__() -> size of S in memory, in bytes
 |  
 |  __sub__(self, value, /)
 |      Return self-value.
 |  
 |  __xor__(self, value, /)
 |      Return self^value.
 |  
 |  copy(...)
 |      Return a shallow copy of a set.
 |  
 |  difference(...)
 |      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.)
 |  
 |  intersection(...)
 |      Return the intersection of two sets as a new set.
 |      
 |      (i.e. all elements that are in both sets.)
 |  
 |  isdisjoint(...)
 |      Return True if two sets have a null intersection.
 |  
 |  issubset(...)
 |      Report whether another set contains this set.
 |  
 |  issuperset(...)
 |      Report whether this set contains another set.
 |  
 |  symmetric_difference(...)
 |      Return the symmetric difference of two sets as a new set.
 |      
 |      (i.e. all elements that are in exactly one of the sets.)
 |  
 |  union(...)
 |      Return the union of sets as a new set.
 |      
 |      (i.e. all elements that are in either set.)