Question: The dir() built-in function.

(a) Start up the Python interpreter. Run the dir() built-in function by simply typing "dir()" at the prompt. What do you see? Print the value of each element in the list you see. Write down the output for each and what you think each is.

(b) You may be asking, so what does dir() do? We have already seen that adding the pair of parentheses after "dir" causes the function to run. Try typing just the name "dir" at the prompt. What information does the interpreter give you? What do you think it means?

(c) The type() built-in function takes any Python object and returns its type. Try running it on dir by entering "type(dir)" into the interpreter. What do you get?

(d) For the final part of this exercise, let us take a quick look at Python documentation strings. We can access the documentation for the dir() function by appending ".__doc__" after its name. So from the interpreter, display the document string for dir() by typing the following at the promt: print dir.__doc__. Many of the built-in functions, methods, modules, and module attributes have a documentation string associated with them. We invite you to put in your own as you write your code; it may help another user down the road.