Python数据基础类型-新建列表

1，遍历列表

　　遍历列表的所有元素，对每个元素执行相同的操作。可使用for循环

magicians = ['alice','david','carolina']
for magician in magicians:
　　print(magician)

运行结果
alice
david
carolina

magicians = ['alice','david','carolina']
for magician in magicians:
    #print(magician)
    print(magician.title() + ", that was a great trick!")
    print("I can't wait to see your next trick, " + magician.title() + ".\n")

print("Thank you, everyone. That was a great magic show!")

运行结果
Alice, that was a great trick!
I can't wait to see your next trick, Alice.

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

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

Thank you, everyone. That was a great magic show!

 2，创建数字列表

　一，列表非常适合用于存储数字集合，函数range（）能够轻松生成一系列的数字。　　

for value in range(1,5):
    print(value)

运行结果
1
2
3
4

　　二，使用range（）创建数字列表。可使用函数list（）将range（）的结果直接转换成列表。还可指定步长。

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

运行结果
[1, 2, 3, 4, 5]

 　　三、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。

　　语法：描述性的列表名 = 【表达式（用于存储到列表中的值）  for循环】

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

View Code

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

result

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

View Code

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

result

　　四、切片

　　1，处理列表的部分元素-称之为切片　

players = ['charles','martina','michael','florence','eli']
print(players[0:3])
print(players[1:4])
print(players[:4])
print(players[2:])
print(players[-3:])
print(players[:-3])

View Code

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

result

　　2，遍历切片

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

View Code

运行结果：
Here are the first three players on my team:
Charles
Martina
Michael

result

　　3，复制列表

3，元组

　　Python的元组与列表类似，不同之处在于元组的元素不能修改。

　　元组使用小括号，列表使用方括号。

　　元组创建很简单，只需要在括号中添加元素，并使用逗号隔开即可。

　　如下实例：

　　

dimensions = (200,50)
#dimensions[0] = 250 修改无组值报错
print(dimensions[0])
print(dimensions[1])

#遍历元组中的所有值，for循环
for dimension in dimensions:
    print(dimension)
@修改元组变量
dimensions = (250,50)
print("\nModified dimensions:")
for dimension in dimensions:
    print(dimension)

View Code

运行结果：
200
50
200
50

Modified dimensions:
250
50

result