had like 20 if statements until I came to senses and got exactly this.

If I'm not mistaken, I think it compares the ascii or unicode number for it. '4' in ascii would be int 52 and '5' would be int 53, '6' is int 54 and so forth so anything below int 53, put a '0' and anything above put a '1'

I did it this way because I wanted to see if it worked but this one also works: return boolean == True

short and sweet!