11 + 56 # This is a comment. It's meant only for humans. 23 - 52 # The "#" tells Python to ignore the rest of the line. 4 * 5 # 4 times 5. 2 ** 5 # 2 to the power of 5 8 / 3 # The "/" is division. Not "\"! #Note: Integer division! like in elementary school. 8 % 3 # The % is the remainder operator #what if we don't want integers? #we need to tell python that we're dealing with 'real' numbers. #We do this by adding a .0 to the end of a number. 8.0/3.0 #Decimals also work but they're bad form. 8./3. #Style and readability are important! 4/0 #lets look at error messages. #Back to slides. #let's looks at dir and help. dir(__builtins__) # All the functions etc that are built in to basic Python. #you can also import 'modules' (which are basically groups of related functions) and apply dir on them. dir(media) import media dir(media) #help tells you about the details of a function of module. help(abs) help(media) #save shell, and look at a bit of code. #Note how we're reusing a number all over. (also makes updating hard) #what if we could save it?