all good

What error? Could you please tell me (posting under my comment below, so that I can be notified at once) the test arrays and the test array and the error message?

I tried the whole code also in another environment and seems to work fine, so I need more info (right under JMurphy's reply to my comment is ok) to fix it.

Thanks :)

Quote from description:

Remember that the resulting composed function may be passed multiple arguments!

...but I guess you figured it out already.

Actually, only one is given in one of the test cases when calling Plugboard() without any arguments for testing empty construction. Honestly, I think it should be Plugboard('') for empty pairing.

Yes, that's the idea.

In this exercise, you are required to understand exception and how to raise an error whenever an input is outside definition.

• if you have to many wires, you should raise an exception (anything is fine, but it will be better if you raise ValueError)

• __init__ takes 2 arguments. One is self which is mandatory, and second, wires which is defaulted to no wire pairings when not defined. I'd suggest google for Python default parameter to understand more.