Marco Islas

Python: Simple HTTP Server on python.

Python have several modules that help you to achieve your goals. This week, on my spare time that is getting every day more scarce I spend time figuring out how to create a Python Web Server, I was planing to use it over an application that I'm developing on ICT Consulting. At the end I didn't use it because I didn't want a "passive" comunication, but probably I will use this code on the CRM Desktop application that we use here.

Anyway, this code may be helpful for you too. I found that creating a small web server is really simple, It starts getting bigger as you add functions to that web server, but the basis is quite simple.

 
import os
import cgi
import sys
from BaseHTTPServer import HTTPServer, BaseHTTPRequestHandler
 
class customHTTPServer(BaseHTTPRequestHandler):
        def do_GET(self):
                self.send_response(200)
                self.send_header('Content-type', 'text/html')
                self.end_headers()
                self.wfile.write('<HTML><body>Get!</body></HTML>')
                return
               
        def do_POST(self):
                global rootnode
                ctype,pdict = cgi.parse_header(self.headers.getheader('Content-type'))
                if ctype == 'multipart/form-data':
                        query = cgi.parse_multipart(self.rfile, pdict)
                self.send_response(301)
                self.end_headers()
                self.wfile.write('Post!')
       
               
def main():
        try:
                server = HTTPServer(('',8080),customHTTPServer)
                print 'server started at port 8080'
                server.serve_forever()
        except KeyboardInterrupt:
                server.socket.close()
 
if __name__=='__main__':
        main()
 
There are two main methods in our small server: do_GET and do_POST, you can figure out what this methods do. Get is quite simple, Post is used to send data to the server, as an example, the file uploading. This is done via POST and many times using "multipat/form-data" as the content type. The Post method here handles that.

Now that you have a custom server, how can you check it?, well, to check GET you can call it from the web browser. For the POST stuff, you can create a simple web form and using your web browser as "action" on it. However, this code can help you:

 
import urllib2
import urllib
import time
import httplib, mimetypes
 
HOST = '127.0.0.1'
PORT = '8080'
 
def post_multipart(host, port, selector, fields, files):
        """
        Post fields and files to an http host as multipart/form-data.
        fields is a sequence of (name, value) elements for regular form fields.
        files is a sequence of (name, filename, value) elements for data to be uploaded as files
        Return the server's response page.
        """

        content_type, body = encode_multipart_formdata(fields, files)
        h = httplib.HTTP(host, port)
        h.putrequest('POST', '/cgi-bin/query')
        h.putheader('content-type', content_type)
        h.putheader('content-length', str(len(body)))
        h.endheaders()
        h.send(body)
        #errcode, errmsg, headers = h.getreply()
        h.getreply()
        return h.file.read()
 
def encode_multipart_formdata(fields, files):
        """
        fields is a sequence of (name, value) elements for regular form fields.
        files is a sequence of (name, filename, value) elements for data to be uploaded as files
        Return (content_type, body) ready for httplib.HTTP instance
        """

        BOUNDARY = '----------ThIs_Is_tHe_bouNdaRY_$'
        CRLF = '\r\n'
        L = []
        if fields:
                for (key, value) in fields:
                        L.append('--' + BOUNDARY)
                        L.append('Content-Disposition: form-data; name="%s"' % key)
                        L.append('')
                        L.append(value)
        if files:
                for (key, filename, value) in files:
                        L.append('--' + BOUNDARY)
                        L.append('Content-Disposition: form-data; name="%s"; filename="%s"' % (key, filename))
                        L.append('Content-Type: %s' % get_content_type(filename))
                        L.append('')
                        L.append(value)
        L.append('--' + BOUNDARY + '--')
        L.append('')
        body = CRLF.join(L)
        content_type = 'multipart/form-data; boundary=%s' % BOUNDARY
        return content_type, body
 
def get_content_type(filename):
        return mimetypes.guess_type(filename)[0] or 'application/octet-stream'
 
def test():
        print  post_multipart(HOST, PORT, 'markuz',
                                        ( ('username','markuz'),  ('another_field','another value')),
                                        (('query','query','Query'), ),
                                   )
 
if __name__ == '__main__':     
     test()
 

#1 Re: Python: Simple HTTP Server on python.

matt Donahoe, <> / Monday 23 March 2009 6:26am  
avatar

what is the "global rootnode" for?

[ Reply (0) ]

#2 Re: Python: Simple HTTP Server on python.

markuz, <E-Mail> / Tuesday 24 March 2009 9:24am  
avatar

Actually, is its not being used.

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