正文
Python列表:元素的修改、添加、删除和排序
小程序:扫一扫查出行
【扫一扫了解最新限行尾号】
复制小程序
【扫一扫了解最新限行尾号】
复制小程序
本文参考自《Python编程:从入门到实践》,作者:Eric Matthes,译者:袁国忠
操作 | 语法 | 举例 | 结果 |
修改元素 | motocycles = ['honda', 'yamaha', 'suzuki'] print (motocycles) motocycles[0] = 'ducati' print (motocycles) | ['honda', 'yamaha', 'suzuki'] ['ducati', 'yamaha', 'suzuki'] | |
添加元素 | 在列表末尾添加元素:append() | motocycles = ['honda', 'yamaha', 'suzuki'] print (motocycles) motocycles.append('ducati') print (motocycles) | ['honda', 'yamaha', 'suzuki'] ['honda', 'yamaha', 'suzuki', 'ducati'] |
在列表中插入元素:insert() | motocycles = ['honda', 'yamaha', 'suzuki'] print (motocycles) motocycels.insert(0, 'ducati') print (motocycles) | ['honda', 'yamaha', 'suzuki'] ['ducati', 'honda', 'yamaha', 'suzuki'] | |
删除元素 | 根据索引删除:del,无法继续使用 | motocycles = ['honda', 'yamaha', 'suzuki'] print (motocycles) del motocycles[1] print (motocycles) | ['honda', 'yamaha', 'suzuki'] ['honda', 'suzuki'] |
删除末尾的元素:pop(),可以继续使用 也可以根据索引删除,如motocycles.pop(0) | motocycles = ['honda', 'yamaha', 'suzuki'] print (motocycles) popped_motocycle = motocycles.pop() print (motocycles) print (popped_motocycle) | ['honda', 'yamaha', 'suzuki'] ['honda', 'yamaha'] suzuki | |
不知道索引时,根据值删除元素:remove(),可以继续使用 | motocycles = ['honda', 'yamaha', 'suzuki', 'ducati'] print (motocycles) too_expensive = 'ducati' motocycles.remove(too_expensive) print (motocycles) print (too_expensive) | ['honda', 'yamaha', 'suzuki', 'ducati'] ['honda', 'yamaha', 'suzuki'] ducati | |
元素排序 | 无返回值,彻底改变原值 永久性排序:sort() 反方向排序:sort(reverse = True) | cars = ['bmw', 'audi', 'toyota', 'subaru'] print (cars) cars.sort() print (cars) cars = ['bmw', 'audi', 'toyota', 'subaru'] cars.sort(reverse = True) print (cars) | ['bmw', 'audi', 'toyota', 'subaru'] ['audi', 'bmw', 'subaru', 'toyota'] ['toyota', 'subaru', 'bmw', 'audi'] |
有返回值,原值不会变 临时性排序:sorted() 反方向排序:sorted(reverse = True) | cars = ['bmw', 'audi', 'toyota', 'subaru'] print (cars) print (sorted(cars)) print (cars) | ['bmw', 'audi', 'toyota', 'subaru'] ['audi', 'bmw', 'subaru', 'toyota'] ['bmw', 'audi', 'toyota', 'subaru'] | |
无返回值,彻底改变原值 永久性反转列表元素的排列顺序:reverse() | cars = ['bmw', 'audi', 'toyota', 'subaru'] print (cars) cars.reverse() print (cars) cars.reverse() print (cars) | ['bmw', 'audi', 'toyota', 'subaru'] ['subaru', 'toyota', 'audi', 'bmw'] ['bmw', 'audi', 'toyota', 'subaru'] | |
有返回值,不会改变原值 临时性反转列表的排列顺序:[: : -1] | num = [1, 2, 3, 4] num_new = num[::-1] print(num_new) print(num) | [4, 3, 2, 1] [1, 2, 3, 4] | |
合并列表 | +或extend | A = [1, 2, 3, 4] B = [5, 6, 7, 8] A = A + B 或 A.extend(B) print(A) | [1, 2, 3, 4, 5, 6, 7, 8] |