# python – Leetcode面试题：请实现一个函数，把字符串 s 中的每个空格替换成”%20″(Python – leetcode interview question: please implement a function to replace each space in the string s with “% 20”)-python

## python – Leetcode面试题：请实现一个函数，把字符串 s 中的每个空格替换成”%20″(Python – leetcode interview question: please implement a function to replace each space in the string s with “% 20”)

### 要求

``s = "we are tester"``
``we%20are%20tester``

### index() 函数语法

``````# index() 方法检测字符串中是否包含子字符串 str

fruits = ['apple', 'banana', 'cherry']

r = fruits.index("cherry")
print(r)  # 2
``````

### 替换函数

``````# -*- coding: utf-8 -*-

def replaceSpace(s):
"""
把字符串 s 中的每个空格替换成"%20
:param s: 字符串
:return:
"""
li = []  # 定义空列表
# 遍历
for i in s:
li.append(i)
# print(li)  ['w', 'e', ' ', 'a', 'r', 'e', ' ', 't', 'e', 's', 't', 'e', 'r']
for i in li:
if i == ' ':
li[li.index(i)] = '%20'
return ''.join(li)

if __name__ == '__main__':
s = "we are tester"
r = replaceSpace(s)
print(r)  # we%20are%20tester
``````

### 方法二

python里面有个replace方法可以直接替换字符串,

``````s = "We are tester"
print(s.replace(" ", "%20"))  # We%20are%20tester
``````

### ——分界线——

``````我们大多数人的努力程度还配不上谈论天赋的地步
``````
————————

### requirement

Input:
Output:

``s = "we are tester"``
``we%20are%20tester``

### Index() function syntax

``````# index() 方法检测字符串中是否包含子字符串 str

fruits = ['apple', 'banana', 'cherry']

r = fruits.index("cherry")
print(r)  # 2
``````

### Substitution function

``````# -*- coding: utf-8 -*-

def replaceSpace(s):
"""
把字符串 s 中的每个空格替换成"%20
:param s: 字符串
:return:
"""
li = []  # 定义空列表
# 遍历
for i in s:
li.append(i)
# print(li)  ['w', 'e', ' ', 'a', 'r', 'e', ' ', 't', 'e', 's', 't', 'e', 'r']
for i in li:
if i == ' ':
li[li.index(i)] = '%20'
return ''.join(li)

if __name__ == '__main__':
s = "we are tester"
r = replaceSpace(s)
print(r)  # we%20are%20tester
``````

### Method 2

Python has a replace method that can directly replace strings,
But most interviewers are not satisfied with this answer because sprite has not had enough years,

``````s = "We are tester"
print(s.replace(" ", "%20"))  # We%20are%20tester
``````

### ——Dividing line——

``````我们大多数人的努力程度还配不上谈论天赋的地步
``````