Does Python have a module for parsing HTTP requests and responses?
Question: httplib (now http.client) and friends all have conn.getresponse() and an
HTTPResponse class, but the server-side operations of conn.getrequest() and an
HTTPRequest class seem to be lacking.

I understand that BaseHTTPServer and BaseHTTPRequestHandler can perform this
functionality, but they don't expose these methods for use outside of the
module.

Essentially what I want is BaseHTTPRequestHandler#parse_request to be a static
method that returns an HTTPRequest object rather than populating member
variables.


Answer: Jeff, to enable parsing I create a small nine-line subclass of the base HTTP
request handler:

    
    
    from BaseHTTPServer import BaseHTTPRequestHandler
    from StringIO import StringIO
    
    class HTTPRequest(BaseHTTPRequestHandler):
        def __init__(self, request_text):
            self.rfile = StringIO(request_text)
            self.raw_requestline = self.rfile.readline()
            self.error_code = self.error_message = None
            self.parse_request()
    
        def send_error(self, code, message):
            self.error_code = code
            self.error_message = message
    

You can now take a string with the text of an HTTP request inside and parse it
by instantiating this class:

    
    
    # Simply instantiate this class with the request text
    
    request = HTTPRequest(request_text)
    
    print request.error_code       # None  (check this first)
    print request.command          # "GET"
    print request.path             # "/who/ken/trust.html"
    print request.request_version  # "HTTP/1.1"
    print len(request.headers)     # 3
    print request.headers.keys()   # ['accept-charset', 'host', 'accept']
    print request.headers['host']  # "cm.bell-labs.com"
    
    # Parsing can result in an error code and message
    
    request = HTTPRequest('GET\r\nHeader: Value\r\n\r\n')
    
    print request.error_code     # 400
    print request.error_message  # "Bad request syntax ('GET')"
    

