[issue39106] Add suggestions to argparse error message output for unrecognized arguments

[conchylicultor]

conchylicultor <etiennefg.pot at gmail.com> added the comment:

I don't think this should have been closed.

[1]  If the user is using sub_parser, the options are not even displayed. For example in our https://github.com/tensorflow/datasets project:

```
$ tfds build mnist --overwritte
usage: tfds [-h] [--helpfull] [--version] {build,new} ...
tfds: error: unrecognized arguments: --overwritte
```

[2] For some programs, there can be 20+ options and having to scroll through the list is not user friendly at all.

[3] Other CLI, like Google absl.flags has this option too and it is very convenient.

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nosy: +conchylicultor

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<https://bugs.python.org/issue39106>
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