操作列表

 遍历整个列表

students = ['zhangsan','lisi','wangwu','zhaoliu']
for student in students:
	print(student)

zhangsan
lisi
wangwu
zhaoliu
[Finished in 0.2s]

　　由于两条print 语句都缩进了，因此它们都将针对列表中的每位学生执行一次。第二条print 语句中的换行符" " （见❶）在每次迭代结束后都插入一个空行，从而整洁地 将针对各位学生的消息编组：

students = ['zhangsan','lisi','wangwu','zhaoliu']
for student in students:
	print(student.title() + ", that was a great trick!")
	print("I can't wait to see your next trick ," + student.title() + ".
")

Zhangsan, that was a great trick!
I can't wait to see your next trick ,Zhangsan.

Lisi, that was a great trick!
I can't wait to see your next trick ,Lisi.

Wangwu, that was a great trick!
I can't wait to see your next trick ,Wangwu.

Zhaoliu, that was a great trick!
I can't wait to see your next trick ,Zhaoliu.

[Finished in 0.3s]

　　在for 循环后面，没有缩进的代码都只执行一次，而不会重复执行。下面来打印一条向全学生感谢的消息，感谢他们的精彩表演。想要在打印给各位魔学生的消息后面打印 一条给全体学生的致谢消息，需要将相应的代码放在for 循环后面，且不缩进：

students = ['zhangsan','lisi','wangwu','zhaoliu']
for student in students:
	print(student.title() + ", that was a great trick!")
	print("I can't wait to see your next trick ," + student.title() + ".
")
    
print("thank you ,everyone ,that was a great magic show!")


Zhangsan, that was a great trick!
I can't wait to see your next trick ,Zhangsan.

Lisi, that was a great trick!
I can't wait to see your next trick ,Lisi.

Wangwu, that was a great trick!
I can't wait to see your next trick ,Wangwu.

Zhaoliu, that was a great trick!
I can't wait to see your next trick ,Zhaoliu.

thank you ,everyone ,that was a great magic show!
[Finished in 0.3s]

　创建数值列表

使用函数range()

for value in range(1,6):
	print(value) 


1
2
3
4
5
[Finished in 0.1s]

使用range() 创建数字列表

numbers = list(range(1,6))
print(numbers)

[1, 2, 3, 4, 5]
[Finished in 0.1s]

指定步长（不断加2和加1）

numbers = list(range(1,11,2))
print(numbers)
numbers = list(range(1,11,1))
print(numbers)

[1, 3, 5, 7, 9]
[1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
[Finished in 0.1s]

创建一个列表，其中包含前10个整数（即1~10）的平方，在Python中，两个星号（** ）表示乘方运算。

squares = []
for value in range(1,11):
	square = value**2
	squares.append(square)
	print(squares)

[1]
[1, 4]
[1, 4, 9]
[1, 4, 9, 16]
[1, 4, 9, 16, 25]
[1, 4, 9, 16, 25, 36]
[1, 4, 9, 16, 25, 36, 49]
[1, 4, 9, 16, 25, 36, 49, 64]
[1, 4, 9, 16, 25, 36, 49, 64, 81]
[1, 4, 9, 16, 25, 36, 49, 64, 81, 100]
[Finished in 0.3s]

为让这些代码更简洁，可不使用临时变量square ，而直接将每个计算得到的值附加到列表末尾：

squares = []
for value in range(1,11):
	squares.append(value**2)
	print(squares)

[1]
[1, 4]
[1, 4, 9]
[1, 4, 9, 16]
[1, 4, 9, 16, 25]
[1, 4, 9, 16, 25, 36]
[1, 4, 9, 16, 25, 36, 49]
[1, 4, 9, 16, 25, 36, 49, 64]
[1, 4, 9, 16, 25, 36, 49, 64, 81]
[1, 4, 9, 16, 25, 36, 49, 64, 81, 100]
[Finished in 0.3s]

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]
>>> min(digits)
0
>>> max(digits)
9
>>> sum(digits)
45

列表解析

列表解析 将for 循环和创建新元素的代码合并成一行，并自动附加新元素

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

[1, 4, 9, 16, 25, 36, 49, 64, 81, 100]
[Finished in 0.3s]

使用列表的一部分　　

切片

players = ['charles','martina','michael','florence','eli']
print(players)
print(players[0:4])
print(players[1:4])


['charles', 'martina', 'michael', 'florence', 'eli']
['charles', 'martina', 'michael', 'florence']
['martina', 'michael', 'florence']
[Finished in 0.2s]

　　

　

players = ['charles','martina','michael','florence','eli']
print(players)
print(players[:4])
print(players[2:])
print(players[-3:])

['charles', 'martina', 'michael', 'florence', 'eli']
['charles', 'martina', 'michael', 'florence']
['michael', 'florence', 'eli']
['michael', 'florence', 'eli']
[Finished in 0.3s]

遍历切片

players = ['charles','martina','michael','florence','eli']
print("here are the first three playerson my team:")
for player in players[:3]:
	print(player.title())

here are the first three playerson my team:
Charles
Martina
Michael
[Finished in 0.2s]

复制列表