def _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 in y<EOL><DEDENT>
Compute the vectorized membership of ``x in y`` if possible, otherwise
    use Python.