test_walker.py 文件源码

def test_visit_after():

    @ast_transformer
    def simplify(node, visit_after, visiting_after, **kwds):
        if isinstance(node, ast.If):
            if not visiting_after:
                visit_after()
                return node

            # This wouldn't work if we didn't simplify the child nodes first
            if (len(node.orelse) == 0 and len(node.body) == 1
                    and isinstance(node.body[0], ast.Pass)):
                return ast.Pass()
            else:
                return node
        else:
            return node

    node = get_ast(dummy_if)
    new_node = simplify(node)

    assert_ast_equal(new_node, get_ast(
        """
        def dummy_if():
            pass
        """))