python wsgi教程4——GET请求

执行之前的程序,然后在浏览器中打开 http://localhost:8051/?a=10&b=w&b=r 这样的url。

环境变量字典中保存了请求信息REQUEST_METHOD和QUERY_STRING。问号之后的内容即为此次请求字符串的值。可以写一个函数对它进行解析,或者直接使用CGI模块的parse_qs函数,它返回一个字典,其值为一个列表。

下面是一个简单的例子:

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#!/usr/bin/env python
from wsgiref.simple_server import make_server
from cgi import parse_qs, escape
html = """
<html>
<body>
<form method="get" action="">
<p>
Age: <input type="text" name="age">
</p>
<p>
Hobbies:
<input name="hobbies" type="checkbox" value="software"> Software
<input name="hobbies" type="checkbox" value="tunning"> Auto Tunning
</p>
<p>
<input type="submit" value="Submit">
</p>
</form>
<p>
Age: %s<br>
Hobbies: %s
</p>
</body>
</html>"""
def application(environ, start_response):
# Returns a dictionary containing lists as values.
d = parse_qs(environ['QUERY_STRING'])
# In this idiom you must issue a list containing a default value.
age = d.get('age', [''])[0] # Returns the first age value.
hobbies = d.get('hobbies', []) # Returns a list of hobbies.
# Always escape user input to avoid script injection
age = escape(age)
hobbies = [escape(hobby) for hobby in hobbies]
response_body = html % (age or 'Empty',
', '.join(hobbies or ['No Hobbies']))
status = '200 OK'
# Now content type is text/html
response_headers = [('Content-Type', 'text/html'),
('Content-Length', str(len(response_body)))]
start_response(status, response_headers)
return [response_body]
httpd = make_server('localhost', 8051, application)
# Now it is serve_forever() in instead of handle_request().
# In Windows you can kill it in the Task Manager (python.exe).
# In Linux a Ctrl-C will do it.
httpd.serve_forever()