>[info] set是一個無序且不重復的元素集合 >  [TOC] <br> ### 集合的定義 #### 創建集合set ```cmd >>> s1=set() >>> s1 set() >>> s2={'a','b','c',1,2,3} >>> s2 {1, 2, 3, 'b', 'c', 'a'} >>> type(s2) <class 'set'> ``` ### 集合的內置方法 #### add(value): 添加元素到集合中 由于集合是無效且不重復的，所以添加相同元素，是不會出現重復添加的。 ```cmd >>> s1=set() >>> s1 set() >>> s1.add('a') >>> s1 {'a'} >>> s1.add('a') >>> s1 {'a'} >>> ``` #### clear()：清除集合中所有元素 ```cmd >>> s1={'a','b','c'} >>> s1.clear() >>> s1 set() ``` #### copy( ):淺拷貝 ```cmd >>> s1={'a','b','c'} >>> s2=s1.copy() >>> s2 {'b', 'c', 'a'} >>> s1.add('d') >>> s2 {'b', 'c', 'a'} >>> s1 {'b', 'c', 'a', 'd'} ``` #### difference(*args, **kwargs): 集合相減，返回新的集合，不影響原集合 ```cmd >>> s1={'a','b','c'} >>> s2={'b','c','d'} >>> s1.difference(s2) {'a'} >>> s1 {'b', 'c', 'a'} ``` 作用等同于 `-`運算： ```cmd >>> s1={'a','b','c'} >>> s2={'b','c','d'} >>> s1-s2 {'a'} >>> s1 {'b', 'c', 'a'} >>> ``` #### difference_update(*args, **kwargs):集合相減，修改原集合 ```cmd >>> s1={'a','b','c'} >>> s2={'b','c','d'} >>> s1.difference_update(s2) >>> s1 {'a'} ``` #### discard(*args, **kwargs)：刪除set集合中的元素 ```cmd >>> s1={'a','b','c'} >>> s1.discard('b') >>> s1 {'c', 'a'} ``` #### intersection(*args, **kwargs):取集合交集，返回新集合 ```cmd >>> s1={'a','b','c'} >>> s2={'b','c','d'} >>> s1.intersection(s2) {'b', 'c'} >>> s1 {'b', 'c', 'a'} ``` 取交集，等同于與`&`運算 ```cmd >>> s1={'a','b','c'} >>> s2={'b','c','d'} >>> s1&s2 {'b', 'c'} ``` #### intersection_update(*args, **kwargs):取集合交集，修改原集合 ```cmd >>> s1={'a','b','c'} >>> s2={'b','c','d'} >>> s1.intersection_update(s2) >>> s1 {'b', 'c'} ``` #### isdisjoint(*args, **kwargs): 判斷集合是否沒有交集 有交集，返回False。無交集，則返回True ```cmd >>> s1={'a','b','c'} >>> s2={'b','c','d'} >>> s3={'d','e','f'} >>> s1.isdisjoint(s2) False >>> s1.isdisjoint(s3) True ``` #### issubset(*args, **kwargs)：判斷集合是否是某個集合的子集 ```cmd >>> s1={'a','b','c'} >>> s2={'a','b','c','d'} >>> s1.issubset(s2) True ``` #### pop():隨機刪除一個元素，返回元素值 ```cmd >>> s1={'a','b','c'} >>> s1.pop() 'b' >>> s1 {'c', 'a'} ``` #### remove(*args, **kwargs):刪除元素 ```cmd >>> s1={'a','b','c'} >>> s1.remove('b') >>> s1 {'c', 'a'} ``` #### symmetric_difference(*args, **kwargs): 取差集，不修改原集合 ```cmd >>> s1={'a','b','c'} >>> s2={'b','c','d'} >>> s1.symmetric_difference(s2) {'a', 'd'} >>> s1 {'b', 'c', 'a'} ``` 取差集，等同于`^`運算 ```cmd >>> s1={'a','b','c'} >>> s2={'b','c','d'} >>> s1^s2 {'a', 'd'} ``` #### symmetric_difference_update(*args, **kwargs): 取差集，修改原集合 ```cmd >>> s1={'a','b','c'} >>> s2={'b','c','d'} >>> s1.symmetric_difference_update(s2) >>> s1 {'a', 'd'} ``` #### union(*args, **kwargs)：取并集，不修改原集合 ```cmd >>> s1={'a','b','c'} >>> s2={'b','c','d'} >>> s1.union(s2) {'d', 'b', 'c', 'a'} ``` 取并集，等同于或`|`運算 ```cmd >>> s1={'a','b','c'} >>> s2={'b','c','d'} >>> s1|s2 {'d', 'b', 'c', 'a'} ``` #### update(*args, **kwargs)，取并集，修改原集合 ```cmd >>> s1={'a','b','c'} >>> s2={'b','c','d'} >>> s1.update(s2) >>> s1 {'d', 'b', 'c', 'a'} ``` <hr style="margin-top:100px"> :-:  ***微信掃一掃，關注“python測試開發圈”，了解更多測試教程！***