Argument error messages display the untranslatable text 'argument ', which should be translatable to other languages, just like it's possible to do with the rest of the constructed error message.

Paste José's comment from PR17169:

This message isn't used (only?) in exceptions... it's a message that is given to the console, to notify the user when she didn't provide correct parameters. For example:
 
```
$ python3 ./drt.py -l
Uso: ./drt.py [-h] [-l LONG_MIN] [-L LONG_MAX] [-v] [-V]
               entrada.json [salida.tok]
./drt.py: error: argument -l/--min-length: se esperaba un parámetro
```

These are console messages localized into Spanish. The "error:" part is translatable, but it's the same word in Spanish than in English. The "argument" part is what isn't translatable, and it's taken from this "exception".

I confirmed that my proposed patch, translating that particular string, allows giving a fully localized console output to the user in Spanish, such as:

`./drt.py: error: parámetro -l/--min-length: se esperaba un parámetro`

Users interact with console's output, so translated the output info is fine to me.
Hi，raymond、paul. What's your opinion?

Closed issue26726 as duplicate of this.