Chapter 03:列表简介

方括号[]表示列表，列表内可放任意类别数据

bicycles = ['trek', 'cannondale', 'redline', 'specialized']
print(bicycles)

['trek', 'cannondale', 'redline', 'specialized']

下标 -1 代表最后一个，-2代表倒数第二个，以此类推

print(bicycles[-1]+'\n'+bicycles[-3])

specialized
cannondale

列表内容可以更改

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

['honda', 'yamaha', 'suzuki']
['ducati', 'yamaha', 'suzuki']

append() 方法用于向列表尾添加元素

motorcycles.append("ducati")
print(motorcycles)

['ducati', 'yamaha', 'suzuki', 'ducati']

insert(idx,str) 方法可在列表任意位置添加新元素,idx代表新元素在列表中的位置

lost_list = ["key","note","pen"]
lost_list.insert(0,"laptop")
print(lost_list)
lost_list.insert(2,"mouse")
print(lost_list)

['laptop', 'key', 'note', 'pen']
['laptop', 'key', 'mouse', 'note', 'pen']

[]可以创建空列表

void_list = []
print(void_list)

[]

如果知道要删除的元素在列表中的位置，可使用del语句。

del motorcycles[0]
print(motorcycles)

['yamaha', 'suzuki', 'ducati']

方法pop()可删除列表末尾的元素并返回被删除元素的拷贝

poped_motorcycle = motorcycles.pop()
print(poped_motorcycle)
print(motorcycles)

ducati
['yamaha', 'suzuki']

pop() 也可删除任意位置处的元素

del_head = motorcycles.pop(0)
print(del_head)
print(motorcycles)

yamaha
['suzuki']

remove() 方法可实现根据内容删除元素，并不返回该元素

PS：仅删除列表中第一次出现过的

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

['honda', 'suzuki', 'ducati']
None

sort() 直接在列表上进行排序

cars = ['bmw', 'audi', 'toyota', 'subaru']
cars.sort()
print(cars)

['audi', 'bmw', 'subaru', 'toyota']

也可以倒序

cars.sort(reverse=True)
print(cars)

['toyota', 'subaru', 'bmw', 'audi']

函数soted() 产生一个排序的副本，不对原列表进行更改

cars = ['bmw', 'audi', 'toyota', 'subaru']
print(sorted(cars))
print(cars)

['audi', 'bmw', 'subaru', 'toyota']
['bmw', 'audi', 'toyota', 'subaru']

reverse() 方法可实现讲列表元素按照下标反转

cars.reverse()
print(cars)

['subaru', 'toyota', 'audi', 'bmw']