集合(set)
集合是由不同可hash的值组成的,里面所有的值都是唯一的,也是无序的
集合的创建
>>>set_test = {"name", "age", "hometown"}
## 把值放入{ }中
>>>lis = ("name", "age", "hometown")
>>>set_test = set(lis)
>>> set_test
{'name', 'age', 'hometown'}
##利用set()函数,把其他类型转换为set
>>> list_test = ["name", "age", "hometown"]
>>> set_test = frozenset(list_test)
>>> set_test
frozenset({'name', 'age', 'hometown'})
##利用frozenset()函数可以创造一个set,并把它放到元组里面
集合的操作
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add(self, *args, **kwargs)
添加值到集合里面
>>> set_test
{'name', 'age', 'hometown'}
>>> set_test.add("hobby")
>>> set_test
{'name', 'age', 'hobby', 'hometown'} -
clear(self, *args, **kwargs)
清空集合
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copy(self, *args, **kwargs)
浅拷贝
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discard(self, *args, **kwargs)
删除某值,没有时不会报错
>>> set_test
{'name', 'age', 'hobby', 'hometown'}
>>> set_test.discard("hobby")
>>> set_test
{'name', 'age', 'hometown'} -
pop(self, *args, **kwargs)
当集合是由列表和元组组成时,set.pop()是从左边删除元素的,并且可以得到被删除的值
>>> set_test
{'name', 'age', 'hometown'}
>>> set_test.pop()
'name'
>>> set_test.pop()
'age' -
remove(self, *args, **kwargs)
删除某值,但是如果没有的话,就会报错
>>> set_test = {'name', 'age', 'hometown'}
>>> set_test.remove("hometown")
>>> set_test
{'name', 'age'} -
update(self, *args, **kwargs)
更新值,可以在set里面添加多个值
>>> set_test = {"Jack", "Mark", "Ada"}
>>> set_test.update(["Jewish", "Obanma", "Anna"])
>>> print(set_test)
{'Obanma', 'Mark', 'Jack', 'Anna', 'Ada', 'Jewish'}
集合的运算
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求交集
>>> set_test1 = {"YuanMing", "Hermaeus", "Chenglong", "Kelan"}
>>> set_test2 = {"YuanMing", "Hermaeus", "ZhangJie","Jack"} >>> test_result = set_test1.intersection(set_test2)
>>> print(test_result)
{'YuanMing', 'Hermaeus'} >>> test_result = set_test1&set_test2
>>> print(test_result)
{'YuanMing', 'Hermaeus'} -
求并集
>>> set_test1 = {"YuanMing", "Hermaeus", "Chenglong", "Kelan"}
>>> set_test2 = {"YuanMing", "Hermaeus", "ZhangJie","Jack"} >>> test_result = set_test1.union(set_test2)
>>> print(test_result)
{'Kelan', 'YuanMing', 'ZhangJie', 'Jack', 'Hermaeus', 'Chenglong'} >>> test_result = set_test1|set_test2
>>> print(test_result)
{'Kelan', 'YuanMing', 'ZhangJie', 'Jack', 'Hermaeus', 'Chenglong'} -
求差集
>>> set_test1 = {"YuanMing", "Hermaeus", "Chenglong", "Kelan"}
>>> set_test2 = {"YuanMing", "Hermaeus", "ZhangJie","Jack"} >>> test_result = set_test1.difference(set_test2)
>>> test_result1 = set_test1.difference(set_test2)
>>> print(test_result1)
{'Kelan', 'Chenglong'} >>> test_result1 = set_test1-set_test2
>>> print(test_result1)
{'Kelan', 'Chenglong'} >>> test_result2 = set_test2.difference(set_test1)
>>> print(test_result2)
{'ZhangJie', 'Jack'} >>> test_result2 = set_test2-set_test1
>>> print(test_result2)
{'ZhangJie', 'Jack'} -
求交叉补集
>>> set_test1 = {"YuanMing", "Hermaeus", "Chenglong", "Kelan"}
>>> set_test2 = {"YuanMing", "Hermaeus", "ZhangJie","Jack"}
>>> test_result = set_test1.symmetric_difference(set_test2)
>>> print(test_result)
{'ZhangJie', 'Jack', 'Kelan', 'Chenglong'}
>>> test_result = set_test1^set_test2
>>> print(test_result)
{'ZhangJie', 'Jack', 'Kelan', 'Chenglong'} -
求集赋值
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symmetric_difference_update(self, *args, **kwargs)
>>> set_test1 = {"Jack", "Mark", "Devid"}
>>> set_test2 = {"Jack", "Marish", "Good"} >>> set_test1.symmetric_update(set_test2)
>>> set_test1.symmetric_difference_update(set_test2) ## 把得到值赋予set_test1
>>> set_test1, set_test2
({'Good', 'Marish', 'Devid', 'Mark'}, {'Good', 'Jack', 'Marish'}) >>> set_test1 ^= set_test2
>>> set_test1
{'Good', 'Marish', 'Devid', 'Mark'} -
intersection_update(self, *args, **kwargs)
>>> set_test1 = {"Jack", "Mark", "Devid"}
>>> set_test2 = {"Jack", "Marish", "Good"} >>> set_test1.intersection_update(set_test2) ##把得到的值赋予set_test1
>>> set_test1, set_test2
({'Jack'}, {'Good', 'Jack', 'Marish'}) >>> set_test1 &= set_test2
>>> set_test1
{'Jack'} -
difference_update(self, *args, **kwargs)
>>> set_test1 = {"Jack", "Mark", "Devid"}
>>> set_test2 = {"Jack", "Marish", "Good"} >>> set_test1.difference_update(set_test2)
>>> set_test1, set_test2
({'Devid', 'Mark'}, {'Good', 'Jack', 'Marish'})
>>> set_test1 = {"Jack", "Mark", "Devid"}
>>> set_test2 = {"Jack", "Marish", "Good"} >>> set_test1 -= set_test2
>>> set_test1
{'Devid', 'Mark'} -
set_test1 |= set_test2
>>> set_test1 = {"Jack", "Mark", "Devid"}
>>> set_test2 = {"Jack", "Marish", "Good"}
>>> set_test1 |= set_test2
>>> set_test1
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子集与父集
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issubset(self, *args, **kwargs)
A.issubset(B) A是B的子集吗? 返回bool
>>> set_test2 = {"Jack", "Marish", "Good"}
>>> set_test1 = {"Jack"}
>>> set_test2.issubset(set_test1)
False
>>> set_test1.issubset(set_test2)
True -
issuperset(self, *args, **kwargs)
A.issuperset(B) A是B的父集吗? 返回bool
>>> set_test2 = {"Jack", "Marish", "Good"}
>>> set_test1 = {"Jack"}
>>> set_test1.issuperset(set_test2)
False
>>> set_test2.issuperset(set_test1)
True -
isdisjoint(self, *args, **kwargs)
返回True如果两个set没有交集
>>> set_test1 = {"Jack", "Mark", "Devid"}
>>> set_test2 = {"Ada", "Marish", "Good"}
>>> set_test1.isdisjoint(set_test2)
True -
<,<= OR >,>=
>>> set_test1 = {"Jack", "Mark", "Devid"}
>>> set_test2 = {"Jack", "Mark"
>>> set_test1 < set_test2
False
>>> set_test1 > set_test2
True