• python set


    复制代码
    >>> num1=[1,2,3,4,5,5,4,3]
    >>> tmp=[]
    >>> for each in num1:
        if each not in tmp:
            tmp.
            
    SyntaxError: invalid syntax
    >>> for each int num1:
        
    SyntaxError: invalid syntax
    >>> for each in num1:
        if each not in tmp:
            tmp.append(each)
    
            
    >>> num1
    [1, 2, 3, 4, 5, 5, 4, 3]
    >>> tmp
    [1, 2, 3, 4, 5]
    >>> num2=list(set(num1))
    >>> num1
    [1, 2, 3, 4, 5, 5, 4, 3]
    >>> num2
    [1, 2, 3, 4, 5]
    >>> num3={1,2,3,4}
    >>> type(num3)
    <type 'set'>
    >>> 
    >>> 1 in num3
    True
    >>> 7 in num3
    False
    >>> num3.add(6)
    >>> num3
    set([1, 2, 3, 4, 6])
    >>> num3.remove(1)
    >>> num3
    set([2, 3, 4, 6])
    >>> num3.remove(4)
    >>> num3
    set([2, 3, 6])
    >>> 
    >>> 
    >>> num4=frozenst([1,2,3])
    
    Traceback (most recent call last):
      File "<pyshell#168>", line 1, in <module>
        num4=frozenst([1,2,3])
    NameError: name 'frozenst' is not defined
    >>> num4=frozenset([1,2,3])
    >>> num4
    frozenset([1, 2, 3])
    >>> type(num4)
    <type 'frozenset'>
    >>> num4[0]
    
    Traceback (most recent call last):
      File "<pyshell#172>", line 1, in <module>
        num4[0]
    TypeError: 'frozenset' object does not support indexing
    >>> 1 in num4
    True
    >>> 4 not in num4
    True
    >>> 4 in num4
    False
    >>> num4.add(1)
    
    Traceback (most recent call last):
      File "<pyshell#176>", line 1, in <module>
        num4.add(1)
    AttributeError: 'frozenset' object has no attribute 'add'
    >>> help(frozenset)
    Help on class frozenset in module __builtin__:
    
    class frozenset(object)
     |  frozenset() -> empty frozenset object
     |  frozenset(iterable) -> frozenset object
     |  
     |  Build an immutable unordered collection of unique elements.
     |  
     |  Methods defined here:
     |  
     |  __and__(...)
     |      x.__and__(y) <==> x&y
     |  
     |  __cmp__(...)
     |      x.__cmp__(y) <==> cmp(x,y)
     |  
     |  __contains__(...)
     |      x.__contains__(y) <==> y in x.
     |  
     |  __eq__(...)
     |      x.__eq__(y) <==> x==y
     |  
     |  __ge__(...)
     |      x.__ge__(y) <==> x>=y
     |  
     |  __getattribute__(...)
     |      x.__getattribute__('name') <==> x.name
     |  
     |  __gt__(...)
     |      x.__gt__(y) <==> x>y
     |  
     |  __hash__(...)
     |      x.__hash__() <==> hash(x)
     |  
     |  __iter__(...)
     |      x.__iter__() <==> iter(x)
     |  
     |  __le__(...)
     |      x.__le__(y) <==> x<=y
     |  
     |  __len__(...)
     |      x.__len__() <==> len(x)
     |  
     |  __lt__(...)
     |      x.__lt__(y) <==> x<y
     |  
     |  __ne__(...)
     |      x.__ne__(y) <==> x!=y
     |  
     |  __or__(...)
     |      x.__or__(y) <==> x|y
     |  
     |  __rand__(...)
     |      x.__rand__(y) <==> y&x
     |  
     |  __reduce__(...)
     |      Return state information for pickling.
     |  
     |  __repr__(...)
     |      x.__repr__() <==> repr(x)
     |  
     |  __ror__(...)
     |      x.__ror__(y) <==> y|x
     |  
     |  __rsub__(...)
     |      x.__rsub__(y) <==> y-x
     |  
     |  __rxor__(...)
     |      x.__rxor__(y) <==> y^x
     |  
     |  __sizeof__(...)
     |      S.__sizeof__() -> size of S in memory, in bytes
     |  
     |  __sub__(...)
     |      x.__sub__(y) <==> x-y
     |  
     |  __xor__(...)
     |      x.__xor__(y) <==> x^y
     |  
     |  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 or more sets as a new set.
     |      
     |      (i.e. elements that are common to all of the 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.)
     |  
     |  ----------------------------------------------------------------------
     |  Data and other attributes defined here:
     |  
     |  __new__ = <built-in method __new__ of type object>
     |      T.__new__(S, ...) -> a new object with type S, a subtype of T
    
    >>> 
    复制代码
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  • 原文地址:https://www.cnblogs.com/wangsicongde/p/7599153.html
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