All language subtitles for 12. Exercise Tricky Counter

Welcome back.

Let's try it.

A simple exercise.

I want you to build a simple counter and this counter is going to count the items in our list.

What does that mean.

Well let's say I have a list and this is a reserved word.

Remember it's an actual word in Python so let's name it my list as a variable.

And this list has 1 2 3 4 5 6 7 8 9 what I want you to do is using looping to loop over this editable

list and sum up the total of the list pauses the video if you need to.

Otherwise let's see how we can do that what I'll do is create a counter variable that will equal to

zero to start off with and then I'll say for item in my list I'm going to counter equals counter plus

item and then at the end I'm going to print counter.

Let's see if this works I'm going to hit run and I get fifty five which if my quick math is right should

be should be correct.

Now when doing this exercise you may have gotten tripped up a bit.

So let's think about this.

Some of you may have made an error where you did the print here but if you did the print here you remember

that it's going to get looped over it's part of this code block because of the indentation and it's

going to print as many times as there are items so you have to make sure that the indentation is like

this so that you get the total.

The other thing that you noticed is that in order for you to keep a counter or a total of all these

items you had to make sure that you had a variable outside of the loop because the loop runs the code

over and over and you needed something on the outside.

That doesn't change because if you moved the counter to zero here well every time the counter would

be reset to zero.

So that by the time we get to 10 counter would be zero.

So you get zero plus 10 which equals 10.

And then you'd get well 10 so you have to be careful here that the indentation is an indication of us

looping and when you loop something and you want to keep a tally or total of something that you have

these issues of making sure that what you want to loop over is inside of this code block but why you

don't want to if you want to have some sort of information that's outside of this loop that you keep

it like this if you weren't tricked by this question.

Good job if you were.

Don't worry it's all part of learning.

I'll see in the next one.

Bob.