Seems like your solution managed to pass in the end.

Assert::That(isValidWalk(V{'e','w','w','w','n','w','w'})

There is no such test, and it should be false. (it could be one of random tests tho)

Hi, unless you can show some evidence that the kata is broken, please don't post as an issue, otherwise you can post as a question. In this case, the reason you get this error message is that the kata expects the funtion name to be likes, whereas your function name is digitize.

This is where you need to start debugging your solution. The first step is to print the input, so even if you fail a test, you can see what the input for that test was. Then you can try to manually go over your code, step by step, to follow along with what it is doing. If you did, you would realize that your code never hits the return statement in some cases. This happens when return statements are buried in some conditional; if the conditional is never True, then the return statement is likewise never executed.
Now, Python functions always return something. In the absence of a return statement, functions simply return None.

Tests usually output something like "x should equal y", where x is your answer and y is the correct answer. Your code only returns a single number, and after hitting a return statement the function ends. Please look carefully at the test output. As I said before, your code will return q as soon as it encounters an odd number: if its_odd < 2: ..., which is true the first time c is odd.

I'm sorry but I don't quite understand what your problem is; could you copy and paste the exact input and test result?

Your code formatting seems off (indentation matters), but from what I can tell it seems your code will return the index of the first odd number it encounters.

Please don't post solutions to the discourse. Use the spoiler flag if you really must.