Encode multipart/form-data in python

multipart.py

_CONTENT_TYPES = { '.png': 'image/png', '.gif': 'image/gif', '.jpg': 'image/jpeg', '.jpeg': 'image/jpeg', '.jpe': 'image/jpeg' }

def _encode_multipart(**kw):
    '''
    Build a multipart/form-data body with generated random boundary.
    '''
    boundary = '----------%s' % hex(int(time.time() * 1000))
    data = []
    for k, v in kw.iteritems():
        data.append('--%s' % boundary)
        if hasattr(v, 'read'):
            # file-like object:
            ext = ''
            filename = getattr(v, 'name', '')
            n = filename.rfind('.')
            if n != (-1):
                ext = filename[n:].lower()
            content = v.read()
            data.append('Content-Disposition: form-data; name="%s"; filename="hidden"' % k)
            data.append('Content-Length: %d' % len(content))
            data.append('Content-Type: %s\r\n' % _guess_content_type(ext))
            data.append(content)
        else:
            data.append('Content-Disposition: form-data; name="%s"\r\n' % k)
            data.append(v.encode('utf-8') if isinstance(v, unicode) else v)
    data.append('--%s--\r\n' % boundary)
    return '\r\n'.join(data), boundary

def _guess_content_type(ext):
    return _CONTENT_TYPES.get(ext, 'application/octet-stream')