定义一个列表，并将列表中的指定位置的两个元素对调。 例如，对调第一个和第三个元素： 对调前 : List = [23, 65, 19, 90], pos1 = 1, pos2 = 3 对调后 : [19, 65, 23, 90] 实例 1 ``` def swapPositions(list, pos1, pos2): list[pos1], list[pos2] = list[pos2], list[pos1] return list List = [23, 65, 19, 90] pos1, pos2 = 1, 3 print(swapPositions(List, pos1-1, pos2-1)) ``` 以上实例输出结果为： ``` [19, 65, 23, 90] ``` 实例 2 ``` def swapPositions(list, pos1, pos2): first_ele = list.pop(pos1) second_ele = list.pop(pos2-1) list.insert(pos1, second_ele) list.insert(pos2, first_ele) return list List = [23, 65, 19, 90] pos1, pos2 = 1, 3 print(swapPositions(List, pos1-1, pos2-1)) ``` 以上实例输出结果为： ``` [19, 65, 23, 90] ``` 实例 3 ``` def swapPositions(list, pos1, pos2): get = list[pos1], list[pos2] list[pos2], list[pos1] = get return list List = [23, 65, 19, 90] pos1, pos2 = 1, 3 print(swapPositions(List, pos1-1, pos2-1)) ``` 以上实例输出结果为： ``` [19, 65, 23, 90] ```