vii iii intermediate topics miscellaneous topics iii mutability and references tuples sets unicode sorted if-else operator continue eval and exec enumerate and zip copy more with strings miscellaneous tips and tricks running your python programs on other computers useful modules importing modules dates and times working with files and directories running and quitting programs zip files getting files from the internet sound your own modules regular expressions introduction syntax summary groups other functions examples math the math module scientific notation comparing floating point numbers fractions the decimal module complex numbers more with lists and arrays random numbers miscellaneous topics