pect to the parser definition. This function is intended as the primary interface to the
        client code.

        :param instring: The input string to be parsed.
        :param parse_all: If set, the entire input string must match the grammar.
        :param parseAll: retained for pre-PEP8 compatibility, will be removed in a future release.
        :raises ParseException: Raised if ``parse_all`` is set and the input string does not match the whole grammar.
        :returns: the parsed data as a :class:`ParseResults` object, which may be accessed as a `list`, a `dict`, or
          an object with attributes if the given parser includes results names.

        If the input string is required to match the entire grammar, ``parse_all`` flag must be set to ``True``. This
        is also equivalent to ending the grammar with :class:`StringEnd`\ ().

        To report proper column numbers, ``parse_string`` operates on a copy of the input string where all tabs are
        converted to spaces (8 spaces per tab, as per the default in ``string.expandtabs``). If the input string
        contains tabs and the grammar uses parse actions that use the ``loc`` argument to index into the string
        being parsed, one can ensure a consistent view of the input string by doing one of the following:

        - calling ``parse_with_tabs`` on your grammar before calling ``parse_string`` (see :class:`parse_with_tabs`),
        - define your parse action using the full ``(s,loc,toks)`` signature, and reference the input string using the
          parse action's ``s`` argument, or
        - explicitly expand the tabs in your input string before calling ``parse_string``.

        Examples:

        By default, partial matches are OK.

        >>> res = Word('a').parse_string('aaaaabaaa')
        >>> print(res)
        ['aaaaa']

        The parsing behavior varies by the inheriting class of this abstract class. Please refer to the children
        directly to see more examples.

        It raises an exception if parse_all flag is set and instring does not match the whole grammar.

        >>> res = Word('a').parse_string('aaaaabaaa', parse_all=True)
        Traceback (most recent call last):
        ...
        pyparsing.ParseException: Expected end of text, found 'b'  (at char 5), (line:1, col:6)
        r