Python列表：元素的修改、添加、删除和排序（python中列表中修改某个元素）

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]