urllib2 upload files

urllib2_upload_files.py

#!/usr/bin/env python
# encoding: utf-8
#
# Copyright (c) 2008 Doug Hellmann All rights reserved.
#
"""
"""
#end_pymotw_header

import itertools
import mimetools
import mimetypes
from cStringIO import StringIO
import urllib
import urllib2

class MultiPartForm(object):
    """Accumulate the data to be used when posting a form."""

    def __init__(self):
        self.form_fields = []
        self.files = []
        self.boundary = mimetools.choose_boundary()
        return
    
    def get_content_type(self):
        return 'multipart/form-data; boundary=%s' % self.boundary

    def add_field(self, name, value):
        """Add a simple field to the form data."""
        self.form_fields.append((name, value))
        return

    def add_file(self, fieldname, filename, fileHandle,
                 mimetype=None):
        """Add a file to be uploaded."""
        body = fileHandle.read()
        if mimetype is None:
            mimetype = ( mimetypes.guess_type(filename)[0]
                         or
                         'application/octet-stream'
                         )
        self.files.append((fieldname, filename, mimetype, body))
        return
    
    def __str__(self):
        """Return a string representing the form data,
        including attached files.
        """
        # Build a list of lists, each containing "lines" of the
        # request.  Each part is separated by a boundary string.
        # Once the list is built, return a string where each
        # line is separated by '\r\n'.  
        parts = []
        part_boundary = '--' + self.boundary
        
        # Add the form fields
        parts.extend(
            [ part_boundary,
              'Content-Disposition: form-data; name="%s"' % name,
              '',
              value,
            ]
            for name, value in self.form_fields
            )
        
        # Add the files to upload
        parts.extend([
            part_boundary,
            'Content-Disposition: file; name="%s"; filename="%s"' % \
               (field_name, filename),
            'Content-Type: %s' % content_type,
            '',
            body,
          ]
          for field_name, filename, content_type, body in self.files
          )
        
        # Flatten the list and add closing boundary marker, and
        # then return CR+LF separated data
        flattened = list(itertools.chain(*parts))
        flattened.append('--' + self.boundary + '--')
        flattened.append('')
        return '\r\n'.join(flattened)

if __name__ == '__main__':
    # Create the form with simple fields
    form = MultiPartForm()
    form.add_field('firstname', 'Doug')
    form.add_field('lastname', 'Hellmann')
    
    # Add a fake file
    form.add_file(
        'biography', 'bio.txt', 
        fileHandle=StringIO('Python developer and blogger.'))

    # Build the request
    request = urllib2.Request('http://localhost:8080/')
    request.add_header(
        'User-agent',
        'PyMOTW (http://www.doughellmann.com/PyMOTW/)')
    body = str(form)
    request.add_header('Content-type', form.get_content_type())
    request.add_header('Content-length', len(body))
    request.add_data(body)

    print
    print 'OUTGOING DATA:'
    print request.get_data()

    print
    print 'SERVER RESPONSE:'
    print urllib2.urlopen(request).read()