I use narratives to learn stuff… and to teach, too
What’s a narrative? It’s a way of connecting events or facts in a form of a story
But I promised to talk about The Function Room…
My mental image of a computer program is that of a small creature working in a room.
When you start writing a program, the Main Room is empty except for some shelves and a small red booklet called “built-in”
Monty — that’s the name of the little creature doing all the hard work — will look around the room whenever you use any name.
more in the next toot
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At the start of the program, if you use a word that’s in the red booklet, Monty will know what to do.
keywords like while
, built-in functions like print
, these are the things in this booklet.
When you create a variable, such as:
day = "Monday"
Monty gets an empty cardboard box, puts the string "Monday"
inside the box and puts a label on the outside of the box which says day
Monty puts this box on a shelf in the Main Room
From now on, if you write day
in your program, when Monty looks around the room he’ll find a box labelled day
and he’ll get its contents—the string "Monday"
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Anyway, let’s get to defining a function:
def do_something_clever(first, second):
"""do some stuff"""
output = first + second
return output
A function is a mini-program within a program.
So, in my mental image of how computer programming works, a function is another room…
When you define a function, you’re creating a new Function Room that’s adjacent to the Main Room.
There’s a door connecting the Main Room to the Function Room.
The label on the door says do_something_clever
, the name of the function.
So, when you use the name do_something_clever
, Monty will look around the Main Room and see the name as a label on a door leading to another room.
If you’ve called the function by adding parentheses, do_something_clever(5, 8)
, Monty will open the Function Room door and go through it.
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However, if the function call was just:
do_something_clever(5, 8)
then Monty doesn’t know what to do with the data he’s holding. So he’ll throw it away in the garbage bin so he can carry on with his work.
What if you write:
print(do_something_clever(5, 8))
Monty will go to the do_something_clever
Function Room, do what he needs to do, and return to the Main Room holding the integer 13
…
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…but he won’t stay there long. Monty finds the name
print
in the built-in red booklet which gives him directions to theprint
Function Room which is elsewhere in Python City.He’ll leave the Main Room to go to the
print
Function Room, taking the integer13
with him.When Monty finishes from the
print
Function Room, he’ll return to the Main Room and carry on with whatever instructions come next.Usual caveat: analogies are not perfect. So don’t take them literally. Literally!
But, our brains react better to narratives rather than random facts. So I find that these ‘stories’ help me understand and remember this stuff so much better…
Hopefully it will help others, too.
If you want to read more on this analogy, you can read this:
https://thepythoncodingbook.com/understanding-programming-the-white-room/
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