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-: So we've just created a program

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that isn't going to error out, hopefully

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at least with value errors and zero division errors.

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But sometimes errors and exceptions can be so severe

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that we do want to stop our programs from running.

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We do wanna catch them like this with the except block, but

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at the same time also stop whatever the program is doing.

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Maybe instead of print, we actually wanna display

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that red here and says,

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"Oh, something bad's happening. Stop that."

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Well, in that case, we either don't use the except block

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or in here we can say, raise ValueError.

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Now, this is rare that you'd have to do this.

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There are some specific use cases,

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but here you would just write a message saying,

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" Hey cut it out",

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so that if I run this,

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well if I type in a valid number,

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again, please enter a number.

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Okay, I'm finally done because I raise a value error

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and it throws in here into the except block.

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So I'd have to remove this.

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And if I remove this like this and hit run

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enter five and look at that, I get a value error.

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"Hey, cut it out."

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So I'm able to throw my own errors.

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So this is really useful,

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if you're creating your own library or tool

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and you wanna let the user know that an error happened

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"I'm not gonna keep doing what you're doing."

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And this could be any type of error.

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You can also do something like exception

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and if I click run here, do five

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I get an exception, "Hey, cut it out."

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The key thing to remember with errors

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is that errors are unavoidable in programming.

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What your job is as a programmer is to be able to

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anticipate these errors, these bugs, these exceptions

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and handle them properly in your programs.

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And some of the biggest errors happen when

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we're trying to accept input from a user

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not just using this input

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but functions, accepting arguments,

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classes accepting different inputs from users

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like method calls and trying to change attributes.

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When the outside world and our programs

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try to communicate with each other,

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errors are bound to happen.

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Our job as programmers is to try and code

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in a way that handles these exceptions gracefully

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and we can anticipate these errors.

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There's no such thing as a perfect program.

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However, we can try and do our best

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to learn from these errors

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and try to manage them so that our programs don't break.

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I'll see you on the next one.

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Bye-bye.