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]