URL Quoting

【URL Quoting】

　　The URL quoting functions focus on taking program data and making it safe for use as URL components by quoting special characters and appropriately encoding non-ASCII text. They also support reversing these operations to recreate the original data from the contents of a URL component.

　　URL quoting函数作用是将数据能够作为url的一部分，包括处理特殊字符，及编码非ASCII文本。quoting函数也支持逆转以还原数据。

urllib.parse.quote(string, safe=’/’, encoding=None, errors=None)

Replace special characters in string using the %xx escape. Letters, digits, and the characters '_.-' are never quoted.

Note that quote(string, safe, encoding, errors) is equivalent to quote_from_bytes(string.encode(encoding, errors), safe).

Example: quote('/El Ni駉/') yields '/El%20Ni%C3%B1o/'.

urllib.parse.quote_plus(string, safe=”, encoding=None, errors=None)

Like quote(), but also replace spaces by plus signs, as required for quoting HTML form values when building up a query string to go into a URL. Plus signs in the original string are escaped unless they are included in safe. It also does not have safe default to '/'.

Example: quote_plus('/El Ni駉/') yields '%2FEl+Ni%C3%B1o%2F'.

在quote的基础上，把空格变为’+’，连’/’也会被转义。

urllib.parse.unquote(string, encoding=’utf-8′, errors=’replace’)

string must be a unquote(), but also replace plus signs by spaces, as required for unquoting HTML form values.

string must be a quote_plus() is used to quote the values, which means spaces are quoted as a '+' character and ‘/’ characters are encoded as %2F, which follows the standard for GET requests (application/x-www-form-urlencoded). An alternate function that can be passed as quote_via is quote(), which will encode spaces as %20 and not encode ‘/’ characters. For maximum control of what is quoted, use quote and specify a value for safe.

The safe, encoding, and errors parameters are passed down to quote_via (the encoding and errors parameters are only passed when a query element is a parse_qs() and parse_qsl() are provided in this module to parse query strings into Python data structures.

【Example】

1、Here is an example session that uses the GET method to retrieve a URL containing parameters:

2、The following example uses the POST method instead. Note that params output from urlencode is encoded to bytes before it is sent to urlopen as data:

　　 POST  encode后的数据要转换为bytes！！！

　　

3、The following example uses an explicitly specified HTTP proxy, overriding environment settings:

　　

4、The following example uses an explicitly specified HTTP proxy, overriding environment settings: