add_trailing_comma.py 文件源码

def visit_Call(self, node):
        argnodes = node.args + node.keywords
        py2_starargs = getattr(node, 'starargs', None)
        if py2_starargs:  # pragma: no cover (<PY35)
            argnodes.append(py2_starargs)
        py2_kwargs = getattr(node, 'kwargs', None)
        if py2_kwargs:  # pragma: no cover (<PY35)
            argnodes.append(py2_kwargs)

        arg_offsets = set()
        has_starargs = bool(py2_starargs or py2_kwargs)
        for argnode in argnodes:
            if (
                    _is_star_arg(argnode) or
                    _is_star_star_kwarg(argnode)
            ):  # pragma: no cover (PY35+)
                has_starargs = True

            offset = _to_offset(argnode)
            # multiline strings have invalid position, ignore them
            if offset.utf8_byte_offset != -1:  # pragma: no branch (cpy bug)
                arg_offsets.add(offset)

        # If the sole argument is a generator, don't add a trailing comma as
        # this breaks lib2to3 based tools
        only_a_generator = (
            len(argnodes) == 1 and isinstance(argnodes[0], ast.GeneratorExp)
        )

        if arg_offsets and not only_a_generator:
            key = Offset(node.lineno, node.col_offset)
            self.calls[key].append(Call(node, has_starargs, arg_offsets))

        self.generic_visit(node)