Using Variables

[github-learning-lab]

Printing Variables

All the file is doing right now is printing the sentence "You rolled a die." But the purpose of rolling a die is to come up with a number, so let's do that now.

We can make a new variable named roll. Variables are simple to make in Python: set the variable equal to what you want it to be. Above the print function, create and set a variable called roll equal to 5 by writing:

roll = 5

We'll want to print that variable, too, so let's change the print function to reflect what our roll variable is set to. This is done through Python's f-string functionality. By putting an f right before the quotes of the string you're printing, you can then print variables within the string. Let's replace the word 'die' in the sentence to our new roll variable. This changes the line to say:

print(f'You rolled a {roll}')

Run the code again, and it should say You rolled a 5. Nice! Now we're getting a number. A die that only rolls 5's isn't useful though, so let's add in the randomness that dice are used for.

Randomizing Variables

Just like a real die, we want the number we roll to be random. We'll need to use a package to do so. Python is full of packages; think of them like tools you can use for specific situations. Just like how you need a shovel to dig a hole, you need the random package to get a random value in Python.

Right now, you should have a main function that contains this:

roll = 5
print(f'You rolled a {roll}')

To use a package, we'll need to import it. At the top of the file, import the package random by writing:

import random 

In general, it's good practice to import all packages at the beginning of the script. Now let's use that package to randomize our roll variable.

To get a random integer with the random package, we'll update the roll line like so:

roll = random.randint(1,6)

The random.randint function takes two integers as parameters. In this case, since we want to emulate a six-sided die, we want to include the range of results that is possible: 1, 2, 3, 4, 5 and 6. Note that the beginning and the end of the range are inclusive bounds. That is, 1 and 6 are possible values, along with integers between them.

Now run the code and put the number you rolled as a comment, and then we'll keep this tutorial rolling!