剑指offer-替换空格

请实现一个函数，将一个字符串中的空格替换成“%20”。例如，当字符串为We Are Happy.则经过替换之后的字符串为We%20Are%20Happy。

class Solution:
    # s 源字符串
    def replaceSpace(self, s):
        # write code here
        sList = []
        for i in s:
            if i == ' ':
                sList.append('%20')
            else:
                sList.append(i)
        return ''.join(sList)

知识点：python关于list和str之间的转化

str-->list

str1 = "12345"  
list1 = list(str1)  
print list1  
  
str2 = "123 sjhid dhi"  
list2 = str2.split() #or list2 = str2.split(" ")  
print list2  
  
str3 = "www.google.com"  
list3 = str3.split(".")  
print list3  

输出为：

['1', '2', '3', '4', '5']  
['123', 'sjhid', 'dhi']  
['www', 'google', 'com']  

list-->str

str4 = "".join(list3)  
print str4  
str5 = ".".join(list3)  
print str5  
str6 = " ".join(list3)  
print str6  

输出为：

wwwgooglecom  
www.google.com  
www google com 

参考链接

https://blog.csdn.net/roytao2/article/details/53433373