Actually, line 46 is referencing the class Girl, so you wouldn't want quotes. Technically, you're supposed to use try/except duck-typing in Python, but I often

Actually, line 46 is referencing the class Girl, so you wouldn't want quotes. Technically, you're supposed to use try/except duck-typing in Python, but I often find that clearer code comes out of assertions where you literally check the type of an object instead of handling errors. This was no exception. (Sorry, bad pun) You might try throwing in a random seed. I just trusted that my system would iterate enough that it wouldn't matter, but if you're getting all boys (I'm not sure that's the case, but you said that you're getting 0 girls...), it could be that for whatever reason, the system might not be advancing the seed. Try inserting the following two lines immediately after import random: from datetime import datetime random.seed(datetime.now())