(files, data)
return body, content_type
Build the body for a multipart/form-data request.

        Will successfully encode files when passed as a dict or a list of
        2-tuples. Order is retained if data is a list of 2-tuples but arbitrary
        if parameters are supplied as a dict.
Build the body for a multipart/form-data request.
Build the body for a multipart / form - data request .
def _encode_files(files, data):
        """Build the body for a multipart/form-data request.

        Will successfully encode files when passed as a dict or a list of
        2-tuples. Order is retained if data is a list of 2-tuples but arbitrary
        if parameters are supplied as a dict.

        """
        if (not files):
            raise ValueError("Files must be provided.")
        elif isinstance(data, basestring):
            raise ValueError("Data must not be a string.")

        new_fields = []
        fields = to_key_val_list(data or {})
        files = to_key_val_list(files or {})

        for field, val in fields:
            if isinstance(val, basestring) or not hasattr(val, '__iter__'):
                val = [val]
            for v in val:
                if v is not None:
                    # Don't call str() on bytestrings: in Py3 it all goes wrong.
                    if not isinstance(v, bytes):
                        v = str(v)

                    new_fields.append(
                        (field.decode('utf-8') if isinstance(field, bytes) else field,
                         v.encode('utf-8') if isinstance(v, str) else v))

        for (k, v) in files:
            # support for explicit filename
            ft = None
            fh = None
            if isinstance(v, (tuple, list)):
                if len(v) == 2:
                    fn, fp = v
                elif len(v) == 3:
                    fn, fp, ft = v
                else:
                    fn, fp, ft, fh = v
            else:
                fn = guess_filename(v) or k
                fp = v
            if isinstance(fp, str):
                fp = StringIO(fp)
            if isinstance(fp, bytes):
                fp = BytesIO(fp)

            rf = RequestField(name=k, data=fp.read(),
                              filename=fn, headers=fh)
            rf.make_multipart(content_type=ft)
            new_fields.append(rf)

        body, content_type = encode_multipart_formdata(new_fields)

        return body, content_type
def _encode_files ( files , data ) : if ( not files ) : raise ValueError ( "Files must be provided." ) elif isinstance ( data , basestring ) : raise ValueError ( "Data must not be a string." ) new_fields = [ ] fields = to_key_val_list ( data or { } ) files = to_key_val_list ( files or { } ) for field , val in fields : if isinstance ( val , basestring ) or not hasattr ( val , '__iter__' ) : val = [ val ] for v in val : if v is not None : # Don't call str() on bytestrings: in Py3 it all goes wrong. if not isinstance ( v , bytes ) : v = str ( v ) new_fields . append ( ( field . decode ( 'utf-8' ) if isinstance ( field , bytes ) else field , v . encode ( 'utf-8' ) if isinstance ( v , str ) else v ) ) for ( k , v ) in files : # support for explicit filename ft = None fh = None if isinstance ( v , ( tuple , list ) ) : if len ( v ) == 2 : fn , fp = v elif len ( v ) == 3 : fn , fp , ft = v else : fn , fp , ft , fh = v else : fn = guess_filename ( v ) or k fp = v if isinstance ( fp , str ) : fp = StringIO ( fp ) if isinstance ( fp , bytes ) : fp = BytesIO ( fp ) rf = RequestField ( name = k , data = fp . read ( ) , filename = fn , headers = fh ) rf . make_multipart ( content_type = ft ) new_fields . append ( rf ) body , content_type = encode_multipart_formdata ( new_fields ) return body , content_type