def content_length(self) -> int:
        """The content-length sent in the header.  Usually not available"""
        if "content-length" in self.headers:
            try:
                return _plain_int(self.headers["content-length"])
            except ValueError:
                pass

        return 0
The content-length sent in the header.  Usually not available
src/werkzeug/datastructures/file_storage.py