urllib模块url编码和解码：

1.urllib.quote，urllib.quote_plus ，urllib.unquote ，urllib.unquote_plus

urllib.quote 说明：

quote(s, safe=‘/‘)

quote(‘abc def‘) -> ‘abc%20def‘

Each part of a URL, e.g. the path info, the query, etc., has a

different set of reserved characters that must be quoted.

RFC 2396 Uniform Resource Identifiers (URI): Generic Syntax lists

the following reserved characters.

reserved = ";" | "/" | "?" | ":" | "@" | "&" | "=" | "+" |

"$" | ","

Each of these characters is reserved in some component of a URL,

but not necessarily in all of them.

By default, the quote function is intended for quoting the path

section of a URL. Thus, it will not encode ‘/‘. This character

is reserved, but in typical usage the quote function is being

called on a path where the existing slash characters are used as

reserved characters.

(END)

urllib.quote_plus 说明：

quote_plus(s, safe=‘‘)

Quote the query fragment of a URL; replacing ‘ ‘ with ‘+‘

实例演示：

In [18]: urllib.quote(‘abc def‘)

Out[18]: ‘abc%20def‘

In [19]: urllib.quote_plus(‘abc def‘)

Out[19]: ‘abc+def‘

2.urllib.urlencode

urlencode(query, doseq=0)

Encode a sequence of two-element tuples or dictionary into a URL query string.

If any values in the query arg are sequences and doseq is true, each

sequence element is converted to a separate parameter.

If the query arg is a sequence of two-element tuples, the order of the

parameters in the output will match the order of parameters in the

input.

(END)

实例演示：

In [21]: urllib.urlencode({‘username‘:‘xixi‘,‘passward‘:‘haha‘})

Out[21]: ‘username=xixi&passward=haha‘

In [23]: urllib.urlencode(((‘username‘,‘嘻嘻‘),(‘passward‘,‘哈哈‘)))

Out[23]: ‘username=%E5%98%BB%E5%98%BB&passward=%E5%93%88%E5%93%88‘