Create a .__str__()

00:00 Now that we have a parent location class and two child classes, let’s define a .__str__() inside of the parent class so that all of the child classes get a nice output as well. def __str__(self): And it takes self.

00:18 And then we’re just going to return another f-string. So first of all, I want the .location_type in there. And here is an advantage of having this defined as an instance attribute is that inside of the curly braces of the f-string, I can say self.location_type.

00:37 And I’m not going to run into this issues with overriding .location_type with a different instance attribute, because this is already an instance attribute.

00:46 So sure, I can still override it, but there’s not going to be any ambiguity then because there is no class attribute basically that I’m shadowing when I overwrite the .location_type instance attribute. Remember what we did earlier for animals?

01:03 We took this little detour with going through the .__class__ attribute and then to the class attribute. And now I’m just skipping that because I defined .location_type directly as an instance attribute. So it’ll make the code a little easier to read.

01:20 All right, and so I’m saying that the specific .location_type has so and so many spaces filled. That would be an interesting information to have.

01:30 So I’ll put in curly braces here and put some code that calculates how many spaces are left. So I’ll say the length of the self.animals list.

01:44 I’m not doing much of a calculation. I’m just going to say so and so many animals are already in that space. And I’m calculating that by getting the current length of the animals list.

01:56 And then I’ll just represent it, putting a forward slash there. And then another curly braces where I’m going to print out self.spaces. So it’ll say so and so many animals are currently in there out of so and

02:10 so many spaces that exist.

02:14 It was a little hard to describe what an f-string is going to do and usually always easier to just view it. So let me run this code and we’ll give it a try.

02:25 Now I should be able to create a Field. I’m going to create an instance of Field and say that there’s 10 animals that can fit on a field. And then if I print() the Field, it’ll tell me the Field has 0 out of 10 spaces filled. Looks good.

02:40 Let’s make a Barn. The Barn is a little smaller than the Field and only holds five animals. And then I can print() the Barn, and the string tells me the Barn has 0 out of 5 spaces filled. Okay, that looks good.

02:55 That is a readable string representation of what’s going on in that Barn or on that Field. And also, it seems to be working so far.

03:04 Next, let’s put in an easier check to figure out whether or not one of those locations is already full.