You have (psuedo)code like this:

    def print_every_file_in(root_path):
       for path in children(root_path):
           if is_file(path):
              print("file: " + path + ", size:" + get_size(path))
           else:
              print_every_file_in(root_path)

If you want to extract the printing part it's trivial in any language:

    def print_file(path):
       print("file: " + path + ", size:" + get_size(path))

    def print_every_file_in(root_path):
       for path in children(root_path):
           if is_file(path):
              print_file(path)
           else:
              print_every_file_in(path)

And you can easily parametrize what function to call on each node.

But in Python it's equally trivial to extract the traversal:

     def every_file_in_path(root_path):
       for path in children(root_path):
           if is_file(path):
              yield path
           else:
              yield from every_file_in_path(path)

     def print_every_file_in(root_path):
        for file in every_file_in_path(root_path):
           print("file: " + path + ", size:" + get_size(path))

or even extract both:

     def print_every_file_in(root_path):
        for file in every_file_in_path(root_path):
           print_file(file)

which for me is a very clean way to implement this and it's nontrivial to do in languages without generators.