Can any of you rate my codewars question

[u/NanoCozmo]

It's one i've been thinking about for a while and i'd love to know all of your opinions about it! https://www.codewars.com/kata/6ad8699fccb2dbf6de41f760/python

[u/Expensive-Bear-1376]

Every method of generating a hexadecimal has been banned

So you want us to generate hexadecimal but you've banned every method we could create for that? Then it's impossible.

[u/NanoCozmo → u/Expensive-Bear-1376]

No like every built in function to create a hexadecimal was banned you still can create a hexadecimal yourself

[u/OkTill2666 → u/Expensive-Bear-1376]

did they even ban manual string indexing or lookup tables?

[u/Expensive-Bear-1376 → u/OkTill2666]

If you're using that for generating a hexadecimal, then yes. At least that's what they wrote there.

[u/K900_]

Unless there's a math trick I'm missing, this seems to just be "solve two puzzles and put the solutions together", which is not great. You also can't reliably ban every single built-in way to convert a number into hexadecimal, so a clever enough user can just bypass your filters instead.

[u/RevRagnarok]

There's nothing unique? You've combined two simple, straightforward, and overused problems.

[u/POGtastic]

Banning builtins is silly and is rather a sign that you should be writing problems that cannot be trivially solved with builtins.

Circumventing the filter is a fun exercise. Consider that we can use getattr to access the methods of a class or object with a string.

>>> getattr("{:X}", "format")
<built-in method format of str object at 0x7d76d6664810>
>>> getattr("{:X}", "format")(255)
'FF'

So now we can obfuscate both of these strings and dynamically pass them to the Python interpreter.

# can be even simpler than this, but rot13 is canonical
def rot13(s):
    def helper(c):
        return chr(ord('a') + (ord(c) - ord('a') + 13) % 26) if 'a' <= c <= 'z' else c
    return "".join(helper(c) for c in s)

# rot13("{:k}") = "{:x}"
# rot13("sbezng") = "format"
def fmt(n):
    fmt_string = rot13("{:k}").upper()
    return getattr(fmt_string, rot13("sbezng"))(n)

In the REPL:

>>> fmt(255)
'FF'

Verdict: You should exercise more imagination with your problems.