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- [Instructor] Before we get into actually

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dealing with exceptions
that occur at run time,

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let's revisit the concept of
an exception for a moment.

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So first, for example,
let's try division by zero

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which we demonstrated
in an earlier lesson.

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As you can see here, we
get a zero division error

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indicating that division by zero occurred.

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Now what you're looking at
once here is a trace back

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and it's telling you information
about not only the type

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of problem that occurred,
but where it occurred

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in your code.

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The code that was executing
when the exception happened

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terminates and in the
context of a IPtyhon session

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like this one you simply
get the next In prompt

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so that you can continue
your interactive session,

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but if this were in a script,
the script would presumably

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terminate at this point
because we don't have any code

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that says what to do if a
zero division error occurs.

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In another case that we saw previously

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where an exception occurred, for example,

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if I'm doing user input and
I prompt the user to enter

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an integer and then the
user types something

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and that value gets returned
by the input function

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let's assume that again
we wanted an integer,

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but the user types something
that's not an integer

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like hello in that case
we get a value error.

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And again it points out
the snippet in which

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the problem occurred,
gives me an error message

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with a little bit of
more information as well.

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In particular the value
hello could not be turned

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into an integer with base 10.

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So these are a couple of
examples of basic exceptions

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that can be encountered
when you're dealing

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with file processing, network connections,

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database processing, they're tend to be

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many more possibilities
for exceptions to occur

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and depending on what it is you're doing

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you may or may not need more robust code

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to deal with those problems as they occur.

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If you're simply in an
interactive session like this one

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you might not need to deal
with a problem you may simply

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execute a new snippet, but if
you're dealing with a script

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that perhaps performs a
larger task you might want

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some more robust code in there.

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And that's what we're
going to start looking at

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in the next example.