Loops (Python)

Loops

> Tutorial

We are now going to look at another type of structure that is just as fundamental as conditions: loops!

A loop lets you repeat instructions several times. There are several types, bounded and unbounded, which we will cover in this part.

while loop

The unbounded while loop has a syntax similar to the if we saw earlier. It runs a block of instructions as long as a condition is met.

Here is an example:

When it runs, this code displays the following in the logs: > Counter is 1 Counter is 2 Counter is 3 Counter is 4 Counter is 5

"At least once" loop

Python doesn't have a do while loop. To run a block at least once and then repeat it as long as a condition is met, we use while True with break (which exits the loop):

for loop

Python's for loop repeats a block for each value in a sequence. With range(n), you get the numbers from 0 to n - 1:

range(1, 6) produces the values 1, 2, 3, 4, 5 (the end bound is excluded).

Attack several times in a row

Our leek has between 10 and 13 TP (thanks to Motivation) and the Pistol only costs 3 TP, so we can use it 4 times at most.

We use a for loop to run the me.useWeapon() method 4 times in a row:

Here our variable i takes the values 0, 1, 2 and 3, so the loop does 4 iterations.

❓ Quiz

What is a loop for?

Running instructions several times Making your code more compact Speeding up part of your code Running instructions in parallel

Which code(s) are correct?

x = 0 while x < 10: x += 2 x = 0 while x < 10 x += 2 x = 0 for i < 10: x += 2 x = 0 for i in range(5): x += 2

Full AI