@property
    def ext(self):
        # raw_ext is either empty string or starts with period, e.g. '.xml'
        raw_ext = posixpath.splitext(self)[1]
        return raw_ext[1:] if raw_ext.startswith('.') else raw_ext
The extension portion of this pack URI, e.g. ``'xml'`` for
dataset/ETHPy150Open python-openxml/python-docx/docx/opc/packuri.py/PackURI.ext