```

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

classSolution:

    # s 源字符串

    defreplaceSpace(self, s):

        # write code here

        res =''

        n =len(s)

        fori inxrange(n):

            ifs[i]==" ":

                res =res+'%20'

            else:

                res =res+s[i]

        returnres

```