Python学习笔记—列表（python中列表的概念）

# _*_ coding:utf-8 _*_

#########列表简介#########

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

print(bicycles)

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

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#访问列表元素

print(bicycles[0].title())

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Trek

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#通过将索引指定为-1，可以让python返回最后一个列表元素

print(bicycles[-1])

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specialized

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#修改、添加和删除元素

#修改元素

motorcycles = ['honda', 'yamaha', 'suzuki']

print(motorcycles)

motorcycles[0] = 'ducati'

print(motorcycles)

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

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

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#在列表末尾添加元素

motorcycles = ['honda', 'yamaha', 'suzuki']

motorcycles.append('ducati')

print(motorcycles)

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

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#在列表中插入元素

motorcycles = ['honda', 'yamaha', 'suzuki']

motorcycles.insert(0,'ducati')

print(motorcycles)

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

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#从列表中删除元素

#使用del语句删除元素

motorcycles = ['honda', 'yamaha', 'suzuki']

del motorcycles[0]

print(motorcycles)

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['yamaha', 'suzuki']

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#使用方法pop()删除列表末尾元素，并让你能够接着使用它

motorcycles = ['honda', 'yamaha', 'suzuki']

poppde_motorcycle = motorcycles.pop()

print(motorcycles)

print(poppde_motorcycle)

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['honda', 'yamaha']

suzuki

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#弹出列表中任何位置处的元素

motorcycles = ['honda', 'yamaha', 'suzuki']

first_owned = motorcycles.pop(0)

print(first_owned)

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honda

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#根据值删除元素

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

motorcycles.remove('yamaha')

print(motorcycles)

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

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#组织列表

#使用方法sort()对列表按字母顺序进行永久性排序

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

cars.sort()

print(cars)

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

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#按与字母顺序相反的顺序排列列表元素

cars.sort(reverse=True)

print(cars)

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

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#使用函数sorted()对列表进行临时排序，如果要按与字母顺序相反的顺序显示列表，也可向函数sorted()传递参数reverse=True。

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

print("Here is the original list:")

print(cars)

print("\nHere is the sorted list:")

print(sorted(cars))

print("\nHere is the sorted list again:")

print(cars)

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Here is the original list:

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

Here is the sorted list:

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

Here is the sorted list again:

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

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#倒着打印列表

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

cars.reverse()

print(cars)

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

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#确定列表的长度

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

print(len(cars))

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4

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#########操作列表#########

#遍历整个列表

magicians = ['alice', 'david', 'carolina']

for magician in magicians:

print(magician)

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alice

david

carolina

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#创建数值列表

#使用函数range()

for value in range(1,5):

print(value)

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1

2

3

4

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#使用range()创建数字列表

number = list(range(1,6))

print(number)

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[1, 2, 3, 4, 5]

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#还可以指定步长

even_numbers = list(range(2,11,2))

print(even_numbers)

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[2, 4, 6, 8, 10]

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#如何将1~10的平方加入到一个列表中

squares = []

for value in range(1,11):

square = value**2

squares.append(square)

print(squares)

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[1, 4, 9, 16, 25, 36, 49, 64, 81, 100]

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#对数字列表执行简单的统计计算

digits = [1,2,3,4,5,6,7,8,9,0]

print(min(digits))

print(max(digits))

print(sum(digits))

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0

9

45

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#列表解析

squares = [value**2 for value in range(1,11)]

print(squares)

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[1, 4, 9, 16, 25, 36, 49, 64, 81, 100]

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#使用列表的一部分

#切片

players = ['charles', 'martina', 'michael', 'florence', 'eli']

print(players[0:3]) #打印前三名队员

print(players[:4]) #没有指定起始索引，Python从开头开始提取

print(players[2:]) #提取从第3个元素到列表末尾所有元素

print(players[-3:]) #输出最后三名队员

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['charles', 'martina', 'michael']

['charles', 'martina', 'michael', 'florence']

['michael', 'florence', 'eli']

['michael', 'florence', 'eli']

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#遍历切片

players = ['charles', 'martina', 'michael', 'florence', 'eli']

for player in players[:3]:

print(player.title())

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Charles

Martina

Michael

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#复制列表

my_foods = ['pizza', 'falafel', 'carrot cake']

friend_foods = my_foods[:]

my_foods.append('cannoli')

friend_foods.append('ice cream')

print("My favorite foods are:")

print(my_foods)

print("\nMy friend's favorite foods are:")

print(friend_foods)

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My favorite foods are:

['pizza', 'falafel', 'carrot cake', 'cannoli']

My friend's favorite foods are:

['pizza', 'falafel', 'carrot cake', 'ice cream']

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#元组（不可变的列表称为元组）

#定义元组

dimensions = (200,50)

print(dimensions[0])

print(dimensions[1])

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200

50

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#遍历元组中的所有值

dimensions = (200,50)

for dimension in dimensions:

print(dimension)

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200

50

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#修改元组变量

dimensions = (400,100)

for dimension in dimensions:

print(dimension)

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400

100

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