David Ton-Lai3,268 Points
Not sure about "menu[choice]()"
I understood Kenneth's explanation for most of the code, but I'm not sure why there are parens after
menu[choice](). I know it's a dictionary, so menu[choice] is refers to the key in the dictionary. Is the
() a special attribute of OrderedDicts?
Chris FreemanTreehouse Moderator 64,102 Points
There is a bit of trickery here that shows off the power of "functions as first class citizens". If the dictionary
menu is populated with values that are functions, then
menu[choice] will return one of these functions.
Since functions can be passed around just like variables, the function can be returned by
menu[choice] as a 'non-executed object which can subsequently be executed by simply added the parens () to signify executing the function.
A longer way to write this would be:
some_func = menu[choice] some_func() # or combining into one statement: menu[choice]()