desired patterns

[ichabod801]

Up to 99, you can do it with two lists:

under_twenty = ['', 'one', 'two', 'three', 'four', 'five', 'six', 'seven', 'eight', 'nine', 'ten', 'eleven', ..., 'nineteen']
twenty_up = ['twenty', 'thirty', 'forty', ..., 'ninety']

Then you can use numeric indexing (divided by ten for twenty_up, hint: use //), and only have three cases to worry about: 0, < 20, >= 20.