file.py 文件源码

def has_file(self):
        '''Return True iff self.data is a FileStorage with file data'''
        if not isinstance(self.data, FileStorage):
            return False
        # filename == None => the field was present but no file was entered
        # filename == '<fdopen>' is for a werkzeug hack:
        #   large file uploads will get stored in a temporary file on disk and
        #   show up as an extra FileStorage with name '<fdopen>'
        return self.data.filename not in [None, '', '<fdopen>']