def _not_in(x, y):
try:<EOL><INDENT>return ~x.isin(y)<EOL><DEDENT>except AttributeError:<EOL><INDENT>if is_list_like(x):<EOL><INDENT>try:<EOL><INDENT>return ~y.isin(x)<EOL><DEDENT>except AttributeError:<EOL><INDENT>pass<EOL><DEDENT><DEDENT>return x not in y<EOL><DEDENT>
Compute the vectorized membership of ``x not in y`` if possible,
    otherwise use Python.