Dictionary Object For Free

hey there how's it going everybody in this video we'll be learning about dictionaries and how we can work with them in Python so dictionaries allow us to work with key value Pairs and if you're coming from another programming language then you may have heard these called hashmaps or associative arrays so when I say that we'll be working with key value pairs these are two linked values where the key is a unique identifier where we can find our data and the value is that data so we can actually think of that almost like a real physical dictionary where we look up word definitions so in that example each word that we look up would be the key and the definition of that word would be the value so let's go ahead and take a look at some examples so let's say that we wanted to represent a student using a dictionary so to do this we could just create a student variable and set this equal to these curly braces and that's how we start our dictionary now within our curly braces here we will first put in our key so let's say that we want a a key of name now we're going to put in a colon to separate our key from our value and for the name here we'll just start off with John and now let's add some more keys and values and to separate these keys and values we're going to put in a comma so next let's put in a key of age and a value of 25 and lastly we'll put in a key of courses and for this value we'll pass in a list of courses here so we'll say math and compy so now let's print out our student and see how that looks so if we save that and run it then we can see see that it prints out all of our keys and values now let's just get a value of one key so to do this we can add square brackets after our dictionary and then specify the key that we want to access so I can put in square brackets here and let's say that we want to access the name of that student dictionary so I'll just pass in the name key and run that and we can see that that gave us that value of that name key now if I wanted the courses instead then I could just pass in uh that courses for the key if I run that then you can see that we got this list of math and compi so we can see that these values in our dictionary can be just about anything our name is a string our age is an integer and the courses are a list now all of our keys are currently strings but they can actually be any immutable data type so usually these will either be strings or integers but there are a few more data types that they can be as well so for example instead of name as our key here if for some reason we wanted this to be an integer so I'll just pass in one so a one is a valid key and now if I access that key of one and run that then you can see that that gave us John but uh I'm going to set that back to be a string for now and keep that as name so what happens if we try to access a key that doesn't exist so for example I'll try to access the key of phone for a phone number so if we run this then we can see that we get a key...