Hi Chris,

> It seems that if, for, else should not be all aligned at the same level, unless there is a new syntax of Python that I do not know.

I'm happy to tell you it's a Python syntax you don't know ☺

The for-else structure reads as "The for searches for something, if the thing is found there's no need to search more, use `break`, if the thing is not found execute the else".

In other words the else is executed if no `break` were executed.

So in the doc:

    for finder in sys.meta_path:
        spec = finder.find_spec(absolute_name, path)
        if spec is not None:
            break
    else:
        msg = f'No module named {absolute_name!r}'
        raise ModuleNotFoundError(msg, name=absolute_name)

it reads:

Search for the module in sys.meta_path (stopping the search as soon as a module is found), but if the module is not found raise an exception.

It's the proper way to write the good old:

    module_found = False
    for finder in sys.meta_path:
        spec = finder.find_spec(absolute_name, path)
        if spec is not None:
            module_found = True
            break
    if not module_found:
        msg = f'No module named {absolute_name!r}'
        raise ModuleNotFoundError(msg, name=absolute_name)

Bests,
-- 
Julien Palard
https://mdk.fr