import ast
 
def build_tree(node):
    def _visit(node, level=0):
        if isinstance(node, (ast.ClassDef, ast.FunctionDef)):
            yield node.name, level
            level += 1
        for child in ast.iter_child_nodes(node):
            yield from _visit(child, level)
    return '\n'.join(f'{"    " * level}{name}' for name, level in _visit(node))
 
source = '''
class Foo:
    def method1(self):
        pass
    def method2(self):
        pass
 
class Bar:
    def method1(self):
        pass
    def method2(self):
        pass
'''
print(build_tree(ast.parse(source)))

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