Python 3 Programming Tutorial - Function Parameters

Key Takeaways

Hello everybody and welcome to another Python 3 basics video. In this video, we're going to carry on with functions. In the last video, you were shown just a very basic function and we didn't use any parameters. In this video, we're actually going to include parameters and give this function more uh functionality. So, uh let's define a function and we're just going to call this function simple addition. And we're going to have num one and num two. And basically when you write this stuff out it you're just making it up like a variable name. Um you can pick anything you want just write it in and it's going to act like a variable within your function. So as usual colon enter and now we will write out this function. Now what we want this function to do is just some simple addition for us. So we're going to say answer equals num one plus num two. So that's going to give us our answer variable. And just for the sake of printing out something else, uh let's also go ahead and print num one is uh and actually we don't need this uh here. Num one is and then num one. Now what we want to do is actually um print our answer too. So let's go ahead and print the answer. So print answer and now it'll print out our answer. So num one is going to be whatever we specify in the num one parameter and the answer is going to be whatever num one plus num two is. Obviously if you put letters or string or whatever in here it's not going to work. So anyway uh enter enter and we'll run simple addition 53. So we'll save that and we'll run it and we get num one is five and then the answer 5 + 3 equals 8. Cool. Easy enough. And there are no limit to the amount of variables that you can have or the amount of parameters that you can have in your function. The only thing you really want to look out for at this point is the order of the variables as well as the quantity of variables. Now uh the order is as follows. So if you really wanted num one to be uh five but instead you did 35 obviously num one is going to be three not five. Now there's a couple of things that you can do uh here. You can one protect yourself somewhat uh by doing something like this. So you could say num one equals 5 and then num 2 equals 3 like so. And you can hit uh you can run that and it's going to work just like it always has. But you're not going to really see people do this too often. But what you could do is you could say num two num one. And so even though they're in a different order uh than we specified that we'd receive them because we're saying it explicitly here um we're allowed to do that. So num one is three. And sure enough that did work. Um so that's going to work for us. Now quantity is also going to be an issue. So let's just revert back to what we were doing before. 35. We run that. That works out for us. But if we have only one variable called, we get an error. Simple addition. Uh missing one required position positional argument. By that same token, if we have 3, five, three or four, let's do that. And we run it, we're going to get another error. It takes two, but three were given. So that's why uh you know quantity is a big deal. Now that's going to be it for this specific video. In the next video I'm going to be covering the default variable assignments because default variables uh can also kind of change up quantity. So soon we'll be throwing away all the knowledge you just learned on quantity. Oh my goodness. Anyway, hopefully you guys enjoyed. If you have any questions, leave them below. As always, thanks for watching. Thanks for all the support and the subscriptions. Until the next video.