You're overriding the 'calendar' variable, holding the module, by the result of your 'calender.month' call, which happens to be a str. Use a different variable name (e.g. 'result') and the error will disappear.

Unrelated, but don't check for 'if x == True' - just do 'if x' and the result will be the same (also allows for any other result than booleans).