In this lesson, we're going to talk about error and exception handling. So the very first thing we want to do is we want to create a new file, and we're going to go ahead and save this file, but I'm going to give it a little bit of a different name. Instead of saving it as some number, I'm going to actually save it as a file called error. The reason is, is that we want to have this as we practice Python, we want to have this available to us, so it's at our fingertips when we want to implement it. So we don't have to remember a number. Now, error handling is a very important feature in Python. The reason it exists is that when we create a program, we need to have as much control over the user's ability to circumvent the proper flow of our program. So for example, if we're required to have an integer and somebody enters dog, if we don't have error handling, what will happen is that it just will not work. The program will fail. So we need to be aware of this. And this is the time that you're going to start thinking about pre-planning your software before you create it. But for here, we're going to use it. So the first thing we're going to do is type while. And the loop is going to kind of capture the user of the software until they enter the correct type of information. So we type in while true and put the colon and that is a statement that says the things that follow must be true or you're not going to get out of here. And the word that we use to do that is called try. So while true, when it comes in, it's going to be true because nothing has happened yet. We're going to create a variable called num one. And we're going to have that equal to an integer that is going to be inputted by the user. So we have an input statement. And we're going to say, let's make it useful. So we'll say enter your pass code. And we want to make sure we don't forget that we have quotation marks. And then at the end, let's format it a little bit, give us space and the closing quote. Now we have two sets of parentheses to close. And now we have a well formed way for the user to enter in a number. At this point, we need to make sure that it gets checked. So what we're going to put is we're going to put a break statement without the break statement. It will continue through the program. So we're telling it stop for a second. Now, there's a few types of common errors when you create a try and accept clause. The one we're going to deal with is the value error. The value error looks at the value that was entered and determines if it meets the criteria set forth in the try statement. So in our case, an integer. So we're going to type accept value error. And you must use it the way it's written. So a capital V capital E. If the program runs into this value error, it is going to print, you entered the wrong passcode, reenter the code.