def __sub__(self, other):
if isinstance( other, basestring ):<EOL><INDENT>other = ParserElement._literalStringClass( other )<EOL><DEDENT>if not isinstance( other, ParserElement ):<EOL><INDENT>warnings.warn("<STR_LIT>" % type(other),<EOL>SyntaxWarning, stacklevel=<NUM_LIT:2>)<EOL>return None<EOL><DEDENT>return self + And._ErrorStop() + other<EOL>
Implementation of - operator, returns :class:`And` with error stop