Can't understand how For Loops work in Python

Question

I'm currently working on a school assignment that involves me learning Python and I'm currently stuck on 'For Loops.' I'm stuck on understanding how they work and their syntax.

I have an example of code I've been trying to wrap my head around but just can't get it.

simple_list = ["Jack", "Dianne", "Alfred", "Erik"]
for x in simple_list:
    print(x)

This is the code I've been focusing on and I don't understand why it prints a name from the simple list. I also want to know what 'in' does as I couldn't find anything online that helped me understand it.

Thanks!

Please repeat [on topic](https://stackoverflow.com/help/on-topic) from the intro tour. These are questions handled quite well by the many Python tutorials and other educational materials on line. As such, this is not a Stack Overflow issue. — Prune, Apr 30 '20 at 21:25
https://stackoverflow.com/questions/4170656/for-loop-in-python — sahasrara62, Apr 30 '20 at 21:27
`for a in b` is perfectly normal English, and in Python it doesn't have any weird meaning or side effect. `for cookie in jar`: do something with every cookie – regardless whether it's chocolate chip, hazelnut, or peanuts. You'll know what it is the moment you pick one. — Jongware, Apr 30 '20 at 21:28
"I couldn't find anything online that helped me understand it." Rlly? :D — Henry Harutyunyan, Apr 30 '20 at 21:28

score 3 · Answer 1 · answered Apr 30 '20 at 21:25

3

You can think like this:

for EVERY ITEM in THIS LIST:
    print(THIS ITEM)

answered Apr 30 '20 at 21:25

Rafael

525
7
20

score 2 · Answer 2 · answered Apr 30 '20 at 21:25

2

items = ["Jack", "Dianne", "Alfred", "Erik"]
for item in items:
    print(item)

Look at it as a for each instead of the class for with indices.

for (each) item in items:
    print(item)

answered Apr 30 '20 at 21:25

Fede Calendino

71
3

score 2 · Answer 3 · answered Apr 30 '20 at 21:25

For loops go over every item in a list. In this case you have a list

simple_list = ["Jack", "Dianne", "Alfred", "Erik"]

Now the for loop is going to look at every item in the list and do whatever is in the for loop with it. In this case, it will print it.

I'd recommend having a look at http://www.pythontutor.com/ to get a better feel for this sort of thing.

Can't understand how For Loops work in Python

3 Answers3