Python列表：元素的修改、添加、删除和排序

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]

转载于:https://www.cnblogs.com/my_captain/p/7643244.html