小白的python进阶历程------09.集合（set ）

Posted 2021-01-08 chen-sang-python

集合（set）

无序性，唯一性，可存放任何数据类型

1).set的格式

set = {"name","age","sex","address","job"}
print(set,type(set))
set1 = set()                                             #定义一个空集合，注意与字典的区别
print(set1)

2).set的运算

&：取交集
|：取并集(保留两个集合独有的元素，在加入它们的交集部分内容)
-：取差集(返回某个集合自己独有的元素，具体返回哪个集合的内容取决于谁在-号的左侧)
^：先取并集，再舍弃它们的交集

set1 = {"name","age",23,"height","address","job"}
set2 = {"name","age","sex","address","job"}
set3 = set1 & set2
print(set3)
set4 = set1 | set2
print(set4)
set5 = set1 - set2
print(set5)
set6 = set1 ^ set2
print(set6)

3).set中的函数

(1).add()：增加一个新的元素到集合中

set = {"name","age","sex","address","job"}
set.add("height")  
print(set)

 

(2).clear()：清空当前列表中的元素，保留空列表

set = {"name","age","sex","address","job"}
set.clear
print(set)                                                 #结果为set()

 

(3).copy()：复制当前列表

set = {"name","age","sex","address","job"}
set2 = set.copy()
print(set2)

 

(4).difference()：取差集（-）

set1 = {"name","age",23,"height","address","job"}
set2 = {"name","age","sex","address","job"}
print(set1.difference(set2))

 

(5).difference_update()：求差集，并赋值给源集合

set1 = {"name","age",23,"height","address","job"}
set2 = {"name","age","sex","address","job"}
set1.difference_update(set2)
print(set1)

 

(6).discard()： 删除集合中指定的元素，如果该集合内没有该元素也不会报错

set = {"name","age",23,"height","address","job"}
set.discard("name")
print(set)

 

(7).intersection()：求交集（&）

set1 = {"name","age",23,"height","address","job"}
set2 = {"name","age","sex","address","job"}
print(set1.intersection(set2))

 

(8).intersection_update()：求交集，并赋值给源集合

set1 = {"name","age",23,"height","address","job"}
set2 = {"name","age","sex","address","job"}
set1.intersection_update(set2)
print(set1)

 

(9).isdisjoint()：判断两个集合是否包含相同的元素，如果没有返回 True，否则返回 False

set1 = {"name","age",23,"height"}
set2 = {"sex","address","job"}
print(set1.isdisjoint(set2))

 

(10).issubset()：判断原始给定集合的所有元素是否都包含在指定集合中，如果是则返回 True，否则返回 False

set1 = {23,"sex"}
set2 = {"sex",23,"address","job"}
print(set1.issubset(set2))

 

(11).issuperset()：判断指定集合的所有元素是否都包含在原始给定集合中，如果是则返回 True，否则返回 False

set1 = {"sex",23,"address","job"}
set2 = {23,"sex"}
print(set1.issubset(set2))

 

(12).pop()：随机删除一个元素

set = {"name","age",23,"height","address","job"}
print(set.pop())

 

(13).remove()：删除集合中指定的元素，如果该集合内没有该元素就报错

set = {"name","age",23,"height","address","job"}
set.remove("name")
print(set)

 

(14).sysmmetric_difference()：先取并集，再舍弃它们的交集（^）

set1 = {"name","age",23,"height","address","job"}
set2 = {"name","age","sex","address","job"}
print(set1.symmetric_difference(set2))

 

(15).sysmmetric_difference_update()：求交叉补集并赋值给源集合

set1 = {"name","age",23,"height","address","job"}
set2 = {"name","age","sex","address","job"}
set1.symmetric_difference_update(set2)
print(set1)

 

(16).update()：更新集合，参数为可迭代对象

set = {"name","age",23,"height","address","job"}
set.update(("weight","salary"))
print(set)

 

(17).union()：求并集（|）

set1 = {"name","age",23,"height","address","job"}
set2 = {"name","age","sex","address","job"}
print(set1.union(set2))