How to check if a specific digit is in an integer

Question

I want to check if, for example, the digit \'2\' is in 4059304593. My aim is to then check if there are any of the digits 1-9 not in my integer. This is what I have tried:

Answer 1

Since you just want to find out which digits aren't in your number:

def not_in_number(n):
    return {*range(10)} - {*map(int, {*str(n)})}

Usage:

>>> not_in_number(4059304593)
{1, 2, 6, 7, 8}

This takes the set of digits ({*range(10)}) and substracts from it the set of digits of your number ({*map(int, {*str(n)})}), created by mapping the set of digit characters to integers. If you find the {*...} notation confusing, you can always use set(...) instead, which will also work for Python 2.7+:

def not_in_number(n):
    return set(range(10)) - set(map(int, set(str(n))))