How to solve the problem with CommandNotFound?

Question

Python

I don't remember exactly what I did, so it ended up being a mistake. Help, please, how to solve?

Traceback (most recent call last):
  File "/usr/lib/command-not-found", line 10, in <module>
    import CommandNotFound
ImportError: No module named CommandNotFound

Answer 1

or you don't have /usr/lib/command-not-found
then you need to install it.
or the necessary dependencies are missing to run it,
then you need to look at what is missing through ldd /usr/lib/command-not-found and install it

Answer 2

Install the CommandNotFound module, obviously.
In general, you need to remember what you did. Telepaths on vacation.