Python技巧100题(二)

在这里插入图片描述

1.extend和列表相加的区别

a = [1, 2, 3]
b = [4, 5, 6]
print(a + b)
[1, 2, 3, 4, 5, 6]

2.查找列表中某个元素第一次出现的索引,从0开始

a = ['how', 'are', 'you']
print(a.index('you'))
2

3.将一个对象插入到列表中

num = [1, 2, 4, 5]
num.insert(2, 'three')
print(num)
[1, 2, 'three', 4, 5]
使用切片方式
num = [1, 2, 4, 5]
num[2:2] = ['three']
print(num)
[1, 2, 'three', 4, 5]

4.删除列表中的元素

num = [1, 2, 3, 4, 5]
num.pop()
print(num)
num.pop(1)
print(num)
[1, 2, 3, 4]
[1, 3, 4]

5.删除列表中指定的元素

num = [1, 2, 3, 4, 5]
num.remove(4)
print(num)
[1, 2, 3, 5]
//remove只会删除第一次出现的元素
num = [1, 2, 3, 4, 5, 4]
num.remove(4)
print(num)
[1, 2, 3, 5, 4]

6.让列表按相反的顺序排列

num = [1, 10, 20, 30, 40, 50]
num.reverse()
print(num)
[50, 40, 30, 20, 10, 1]

num = [1, 10, 20, 30, 40, 50]
print(num[::-1])
[50, 40, 30, 20, 10, 1]

7.表示只包含一个元素的元组

 n = (1)
 print(type(n))
 <class 'int'>
 n = (1,)
 print(type(n))
<class 'tuple'>

8.批量替换字符串中的元素

a = 'how are you'
print(a.replace('y', 'we'))
how are weou

9.把字符串按照空格进行拆分

a = 'how are you'
print(a.split())
['how', 'are', 'you']

10.取出字符串首位的空格

a = '       how are you'
print(a.strip())
how are you

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转载自blog.csdn.net/qq_45924653/article/details/108080904
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