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You already know that when you try to do something that doesn't make sense, for example, trying to

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add 12.3 to the string high, you get an error.

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So that is the error.

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But what you probably don't know yet is that there are two major types of errors in Python.

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You have syntax errors and then you have exceptions.

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So we have been referring to these as just errors.

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But in this code experiment, video today will explain you the distinction so that you can distinguish

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what syntax errors are and what exceptions are.

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So for that, we're going to be working on our app.

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And here is what I would like you to try for.

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Now.

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So please go under live where the complete condition is.

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So where we check if the user command starts with complete and then we have this try block where we

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try to get the number after the complete command.

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So if the user enters complete three, then we get the part of the index nine, which should give us

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the number and then we have the file operation here.

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Then we remove the to do with that number from the list and we write it to do in the list.

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Now what happens if we remove these brackets here?

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So try to think what will happen.

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We do have this try and accept block Right.

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So that means the interpreter should try to execute this block.

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If it finds an error in that block of code, then it should execute these lines under except that's

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how try and accept works.

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But is that true?

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So are we going to get this printed out?

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So let's try run and this is what we get.

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Syntax error closing in parentheses does not match opening parentheses.

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So why didn't the try accept block handle the error?

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Why do we get a python error here when we were expecting this to be executed?

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Well, the reason is that this here is a syntax error and the try accept block only catches exceptions.

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What is the difference between a syntax error and an exception?

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Well, let's suppose that you are sending an email to someone and on your browser you have a grammar

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checker.

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So that's Checker is checking for grammar errors.

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Maybe you forgot a period or you typed in a word incorrectly so that grammar checker will check for

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syntax errors.

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So when the grammar checker tells you that oh, everything is okay, then you send all the email to

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a person.

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But then the fact that the syntax is correct doesn't mean your email content doesn't have issues.

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So the grammar checker is only able to check for syntax errors, but then the person on the other side

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they can check for logical errors.

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So maybe you said that oh, there is a file in the attachment, but you forgot to attach a file in that

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email.

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So that would be some sort of logical errors which the grammar checker cannot check.

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Similarly with the Python interpreter, there are two instances of that interpreter program.

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So first the interpreter checks your code for syntax errors.

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It doesn't go into the logic of the code itself.

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It doesn't check conditions, it doesn't check try accept blocks.

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So it just looks at the syntax model.

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IDs also have utilities integrated, which also are able to check for syntax errors.

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So all these other lines that you see are suggestions by the OR IDE.

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And then when you run the codes you get the actual source of the error, which in our case points to

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line 46.

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So that's one in there where we have a missing square bracket.

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So that is a syntax error.

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Now sometimes you'll also see that syntax errors are referred by people as just errors, and logical

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errors are referred to as exceptions.

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So a logical error, for example, would be something like if we try to remove an item using an index

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which does not exist in the list.

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So for example, if the list has five items but we try to remove eight here, so the item with index

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eight, then we would get an exception.

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So in other words, if I open the python console in here, so if we have a list and we have A and B

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as items than a dot pop and you say remove item with index five, that is not a syntax error.

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So this is an exception, although you will see people, almost anyone will just say, Oh, we got an

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error.

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So they refer to errors in general to syntax errors and exceptions as well.

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So from a practical point of view, the difference between syntax errors and exceptions doesn't matter

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as much as it matters from the theoretical point of view.

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So you should be aware that these differences exist this way you have a better understanding of how

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your programs work.

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It is beneficial in certain cases, such as in here.

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When you use this try except block.

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Now you understand that a syntax error is not code from this block because of the way the interpreter

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works.

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So it has this grammar checker component which checks the syntax first, and then it has the actual

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interpreter which interprets what you were trying to say through the correct syntax.

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Once the syntax is correct, the grammar checker gives the green light, then the interpreter component,

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which understands the language, goes on and translates the instructions into machine language.

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Then your processor processes the information and it gives the output on your computer screen.

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And so that was the experiment I wanted to try for today.

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And I'll talk to you in the next videos.

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See you.