def matchOnlyAtCol(n):
    """Helper method for defining parse actions that require matching at
    a specific column in the input text.
    """
    def verifyCol(strg,locn,toks):
        if col(locn,strg) != n:
            raise ParseException(strg,locn,"matched token not at column %d" % n)
    return verifyCol
Helper method for defining parse actions that require matching at
    a specific column in the input text.
    
stackoverflow/venv/lib/python3.6/site-packages/pip-19.0.3-py3.6.egg/pip/_vendor/pyparsing.py