url中常见的符号的编码

In [14]: import urllib

In [15]: urllib.unquote("%3a")
Out[15]: ':'

In [16]: urllib.unquote("%2f")
Out[16]: '/'

In [17]: urllib.unquote("%3f")
Out[17]: '?'

In [18]: urllib.unquote("%26")
Out[18]: '&'

In [19]: urllib.unquote("%25")
Out[19]: '%'

In [20]: urllib.unquote("%3d")
Out[20]: '='

In [21]: urllib.unquote("%2b")
Out[21]: '+'