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hello everyone my name is Ja and today
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I'm going to teach you how to use TR
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except else finally in this Python
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tutorial so the try and except statement
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at python is a control flow statement
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that is used for you to handle the
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errors as they happen in your code so
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the idea is to you that you run a block
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of code and if there's an error you run
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in something else uh and this prevents
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your code from breaking because whenever
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you have like exceptions like this hat
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run time you can say that okay one
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divided by 0 that you are not allowed to
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do this but you want to print one
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divided by 0 then you cannot do a
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division by zero so the code will return
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that error everything will break and
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your code won't be able to process any
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line that comes after that exception so
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in order to handle this we need to use
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the try an accept statement and return
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code within it so we can copy that
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example that we had and do try so that's
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the structure you do try and then you
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accept and you trade there was an
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error so we say okay if this breaks then
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return that error and in this case you
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can see that the code managed to to work
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so if you were to reprint hello here uh
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it would still execute properly because
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you wrapped in your error whereas if I
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were to come back here and I wanted to
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print hello at the end it would never
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have printed it so this is the the very
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very basic and powerful thing that uh
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try and except Sofer is it allows you to
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prevent whatever uh to predict whatever
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is coming up and to fix your code so
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that your code doesn't break when uh
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something happens so if we can also
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return uh the name of the exception
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here here as exception name so we could
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say okay there was an error and we could
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just return that exception name right
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there there was an an error division by
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zero if you don't know that this is a
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division uh by zero what you could do is
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just say exception so you just say
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whatever exception you get then return
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the name of the ex exeption so if it's
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not a division by zero then in this case
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it wouldn't uh break so let's say you
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want to do int hello in this case it
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would return inv invalid literal base
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that's pretty much everything you need
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to know for most of the use case that
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you'll get as you go further into uh the
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the logic here is you can have uh this
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example and maybe you want to do the
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exception and if it works then so you
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try and accept and if it works just
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print uh something else
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so there was no error and
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X so you could say okay if you have this
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uh there is a division error because you
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cannot do this but let's say you want to
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do a real division that works then you
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can do 10 ided by two and it will see
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that if it manages to uh run the code
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then else it also uh will return
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something that you wanted so it returns
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error next you can have the finally
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statement something that is not used as
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much as the others uh but the final St
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statement allows you to run code
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regardless of if there was an exception
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or not so one thing you can have is
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let's say we have try and accept and we
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division but we can use the finally
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keyword and if there is an error or if
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there's no error you write something
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that uh try and except has finished
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executing so you can run this so
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regardless of if there is an error if
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you do 10 divided by two you wrote like
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you can divide by zero but if we run
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something uh then it will return try and
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accept it will always return try and
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execution you can also use uh the raise
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statement the raise statement is the
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keyword that is used to raise your own
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exception in your code so if you build
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like code that you know that people are
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going to use sometimes you want to
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actually uh uh raise an exception so
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let's say this best TV show and my best
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TV show ever is Dawson everybody loves
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Dawson I don't want to wait you know
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that TV show I don't know uh it's really
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crappy Tv show uh but the best TV show
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and if best TV show is not equal to How
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I Met Your Mother which is actually the
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best TB show ever uh then you raise an
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exception so I my code is very important
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here uh if people write something that
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is not exactly what I want uh I just
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raise an exception and I can throw in uh
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whatever exception I want like if you
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just put a best TV show equal dson then
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you raise an exception this is a dumb
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answer and in this case I have raised my
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own exception in my code uh and this is
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essentially what the libraries have done
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uh for you to know what's going on in
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the code so thank you very much this is
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over for try accept and finally uh And
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subscribe to my Channel or follow on my
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website you'll find a lot of resources
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for python for beginners thank you very
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much see you next time
