Original subtitles

0 So you are a teacher and you wanted to calculate the average grades of your students. 1

And do we do that using this algorithm here and this data structure to store the grades. 2

The problem here is you don't know which grade is of who. 3

So while a lise is a good data structure to store an array of items, it's not good enough when these 4

items have some sort of identity attached to them. 5

In that case you want to use a dictionary. 6

Let's say student grades curly brackets. 7

That's a syntax for a dictionary. 8

And then you use names of your students. Let's say Marry, a colon. 9

Make some space or not, whatever you prefer. 10

But it's good to have a space there to make it more readable. 11

And then you write the grade of Merry. 12

Let's say Sim, 8.8. 13

John colon, 7.5. 14

So the difference between the dictionary and the list is the brackets, different brackets. 15

And then this is considered an item in a dictionary. 16

This is considered an item in a list. 17

So items in a dictionary are made of keys. 18

This is a key, and values. 19

This is a value. A list would be more appropriate if we had to store for example an array of temperature values. 20

Let's say Monday had these temperatures. Monday temperatures. 21

And lastly how do we calculate the average when we have a dictionary? Since these are pairs of keys 22

and values. 23

You can't just make the sum like that. 24

You need to specify the sum of what you want to get. 25

So student grades and if you check dir dict for dictionary, you'll see that dictionaries have these 26

values which is a method, dict.values it is a method and it provides a view of a dictionary of values. 27

In simple words 28

it gives you the values of a dictionary. 29

So if you get this dictionary, Q for quit here, paste it here, and see student_grades.values and that 30

will give you this data type. 31

So it's still a data type. 32

It does look like at list, it's not exactly a list, but it behaves like a list with these three values 33

there. 34

So it's a dict values type. 35

That method produces this type and therefore you can add that in there. 36

Don't forget the parentheses. 37

Don't forget to save. 38

And don't forget to execute to give the output and this is the average value of a dictionary of values. 39

To get the keys of a dictionary 40

just do keys and you get this dict keys type with the keys of the dictionary as items of that dict keys 41

arrays.