‫Welcome back.
‫In this video, I want to talk about the idea of toothy and falsely.
‫What do they mean?
‫And you'll hear this a lot in Python programming.
‫You see, up until now, you've used booleans here as values.
‫So it was really easy.
‫If true and true, then run this code.
‫But Python can do other things as well.
‫For example, if this was five and this was, let's say hello, what do you think will happen here in
‫our program?
‫Well, if I click Run.
‫You are old enough to drive and you have a license.
‫Is that what you expected?
‫And this is because what Python does underneath the hood is actually convert these to booleans for you.
‫So it's almost as if it is doing this remember type conversion where converting the type.
‫To bullion as soon as we get to this if statement because python is saying hey I want.
‫True or false I don't care what is old is I don't care what is licensed is just give me true or false
‫so I know whether to do this or to go to the else block.
‫Now, if I was to just print.
‫Let's do this here.
‫Let's do print bullion.
‫Hello?
‫And then finally, print bullion.
‫Five.
‫Let's see what we get.
‫We get true.
‫True.
‫And this is what we call a truth value in Python.
‫That is it's a truth we value because if we run the Boolean type conversion on it, it evaluates into
‫true what's a false value.
‫Well, if I do zero and if I do, let's say an empty string and I click run.
‫Those are falsely that is it's not actually false, but it is false because if we run Boolean on it
‫to Python, it's going to say, oh, this is false and zero, that's false.
‫And that kind of makes sense, right?
‫And if you actually go to StackOverflow, if you've never seen StackOverflow before, if you ever have
‫programming questions and you're Googling them, usually the top five answers will contain either one
‫or two StackOverflow answers.
‫And basically what happens is people ask questions like, what is truth and false in Python?
‫And you get answers.
‫So you can see over here that it has four answers and you usually look for the checkmark, which means
‫that this is a verified answer.
‫It means that, hey, this question owner has accepted it as the best answer.
‫So the person who asked this question just said, Yeah, this is the right answer, this is the best
‫one.
‫But you also have other people voting.
‫So you can see that this answer received 46 marks, and although it was marked as the correct answer
‫by the user, maybe somebody else came along later on and gave an even better answer.
‫So now we have 123 upvotes and you see that this answer is a lot better.
‫All values are considered truth except for the following.
‫So you can actually see here that in Python, these values are considered falsely.
‫You can see zero here.
‫You can see an empty string here.
‫And then there's a few other ones.
‫Empty set.
‫You have an empty dictionary, empty list, empty tuple.
‫You have decimals, you have things like fractions, you have 0.0 false is that and also none is falsely
‫so that if I type in none here.
‫That's false, too.
‫Now, you don't need to memorize this because most of the time it's it makes sense.
‫Right.
‫But it helps us do conditional logic very nicely.
‫For example, let's remove this and let's say that we have a user and this user has to have a password
‫and a username.
‫If, let's say the username is Johnny and the password is one, two, three.
‫Well, instead of me saying, hey, if this user has password and username and we're not checking if
‫the username exists or password exists, we just want to make sure, Hey, did this person fill out
‫the form and did they try to submit a username and password?
‫I can just simply say password and username.
‫And I don't have to worry about converting this to a bullion or anything like that, because if password
‫and username exist, then try to log them in and you see that it reads a lot nicer because each one
‫of these get evaluated into a truthful and false value.
‫It's a nice little feature to keep Python.
‫Well, nice and simple and reading like English.
‫I'll see you in the next video.
‫Bye bye.