第 3 章 列表简介

索引 -1 返回列表最后一个元素，-2 返回倒数第二个列表元素，依次类推。

在列表中添加元素

在末尾添加元素 - append

motorcycles = ['honda', 'yamaha', 'suzuki']
motorcycles.append('ducati')
print(motorcycles) # ['honda', 'yamaha', 'suzuki', 'ducati']

在列表中插入元素 - insert

motorcycles = ['honda', 'yamaha', 'suzuki']
motorcycles.insert(0, 'ducati')
print(motorcycles) # ['ducati', 'honda', 'yamaha', 'suzuki']

从列表中删除元素

根据索引删除元素

del

使用 del 可删除列表中具体索引位置的元素。

motorcycles = ['honda', 'yamaha', 'suzuki']
del motorcycles[0]
print(motorcycles) # ['yamaha', 'suzuki']

pop

pop() 弹出列表中最后一个元素并返回该元素。可以通过传入索引，弹出索引位置处的元素。

motorcycles = ['honda', 'yamaha', 'suzuki']
last_owned = motorcycles.pop()
print(motorcycles) # ['honda', 'yamaha']
print(last_owned) # suzuki

motorcycles = ['honda', 'yamaha', 'suzuki']
first_owned = motorcycles.pop(0)
print(motorcycles) # ['yamaha', 'suzuki']
print(first_owned) # honda

根据值删除元素

remove

remove() 删除列表中第一个指定的值。

motorcycles = ['honda', 'yamaha', 'suzuki']
motorcycles.remove('honda')
print(motorcycles) # ['yamaha', 'suzuki']

motorcycles = ['honda', 'yamaha', 'suzuki', 'honda']
motorcycles.remove('honda')
# 只删除了第一个
print(motorcycles) # ['yamaha', 'suzuki', 'honda']

组织列表

使用 sort() 对列表永久排序

motorcycles = ['honda', 'yamaha', 'suzuki']
motorcycles.sort()
print(motorcycles) # ['honda', 'suzuki', 'yamaha']

传入 reverse=True 可以倒序排列

motorcycles = ['honda', 'yamaha', 'suzuki']
motorcycles.sort(reverse = True)
print(motorcycles) # ['yamaha', 'suzuki', 'honda']

使用 sorted() 对列表临时排序

motorcycles = ['honda', 'yamaha', 'suzuki']
print(sorted(motorcycles))  # ['honda', 'suzuki', 'yamaha']
print(motorcycles)  # ['honda', 'yamaha', 'suzuki']

可以传入 reverse=True 作为 sorted() 第二个参数对列表进行临时倒序排序

motorcycles = ['honda', 'yamaha', 'suzuki']
print(sorted(motorcycles, reverse = True))  # ['yamaha', 'suzuki', 'honda']
print(motorcycles)  # ['honda', 'yamaha', 'suzuki']

使用 reverse() 倒着打印列表

motorcycles = ['bmw', 'audi', 'toyota', 'subaru']
motorcycles.reverse()
print(motorcycles)  # ['subaru', 'toyota', 'audi', 'bmw']

使用 len() 确定列表长度

motorcycles = ['bmw', 'audi', 'toyota', 'subaru']
print(len(motorcycles)) # 4