Python_ overriding collections

Class Set (object):
def __init__ (Self,data=none):
if data = = None:
Self.__data = []
Else
If not hasattr (data, ' __iter__ '):
#提供的数据不可以迭代, instantiation failed
Raise Exception (' must provide an iterative data type ')
temp = []
For item in data:
#集合中的元素必须是可哈希
Hash (item)
If not item in temp:
Temp.append (item)
Self.__data = Temp

#析构函数
def __del__ (self):
Del Self.__data

#添加元素, the requirement element must be hashed
def add (self, Other):
Hash (Other)
If and not in Self.__data:
Self.__data.append (Other)
Else
Print (' element already exists, operation is ignored ')

#删除元素
def remove (Self,other):
If and in Self.__data:
Self.__data.remove (Other)
Print (' delete succeeded ')
Else
Print (' element not present, delete operation ignored ')

#随机弹出并返回一个元素
def pop (self):
If not self.__dat:
Print (' collection is empty, popup operation ignored ')
Return
Import Random
Item = Random.choice (Self.__data)
Self.__data.remove (item)
Return item

#运算符重载, set differential set operation
def __sub__ (self, Other):
If not isinstance (Other,set):
Raise Exception (' type error ')
#空集合
result = Set ()
#如果一个元素属于当前集合而不属于另一个集合, add
For item in Self.__data:
If Item not in Other.__data:
Result.__data.append (item)
return result

#提供方法, set differential set operation, reuse the above code
def difference (self,other):
Return Self-other

#| operator overloading, set merge set operation
def __or__ (self, Other):
If not isinstance (Other,set):
Raise Exception (' type error ')
result = Set (self.__data)
For item in Other.__data:
If Item not in Result.__data:
Result.__data.append (item)
return result

#提供方法, set merge set operations
Def union (Self,otherset):
return Self | Otherset

#& operator overloading, set intersection operation
def __and__ (self, Other):
If not isinstance (Other,set):
Raise Exception (' type error ')
result = Set ()
For item in Self.__data:
If item in Other.__data:
Result.__data.append (item)
return result

#^ operator overloading, set symmetric difference set
def __xor__ (self, Other):
Return (Self-other) | (other-self)

#提供方法, set symmetric differential set operation
def symetric_difference (Self,other):
Return self ^ Other

#== operator overload to determine whether two sets are equal
def __eq__ (self, Other):
If not isinstance (Other,set):
Raise Exception (' type error ')
If sorted (self.__data) = = Sorted (other.__data):
Return True
Return False

#> operator overloading, collection contains relationships
def __gt__ (self, Other):
If not isinstance (Other,set):
Raise Exception (' type error ')
If self! = Other:
Flag1 = True
For item in Self.__data:
If Item not in Other.__data:
#当前集合中有的元素不属于另一个集合
Flag1 = False
Break
Flag2 = True
For item in Other.__data:
If Item not in Self.__data:
#另一集合中的元素不属于当前集合
Flag2 = False
Break
If not Flag1 and Flag2:
Return True
Return False

#>= operator overloading, collection contains relationships
def __ge__ (self, Other):
If not isinstance (Other,set):
Raise Exception (' type error ')
return self = = other or self > Other

#提供方法 to determine whether the current collection is a true subset of another collection
def issubset (Self,other):
Return Self<other

#提供方法 to determine whether the current collection is a superset of another collection
def issuperset (Self,other):
return self > Other

#提供方法, clears all elements of the collection
def clear (self):
While Self.__data:
Del Self.__data[-1]
Print (' Collection emptied ')

#运算符重载 so that the collection can iterate
def __iter__ (self):
Return iter (Self.__data)

#运算符重载, the in operator is supported
def __contains__ (self, item):
Return item in Self.__data

#支持内置函数len ()
def __len__ (self):
Return Len (self.__data)

#直接查看该类对象时调用该函数
def __repr__ (self):
Return ' {' +str (self.__data) [1:-1]+ '} '

This function is called when the #使用print () function outputs the class object
__str__ = __repr__

Python_ overriding collection