Python for Absolute Beginners Transcripts
Chapter: Error handling
Lecture: Concept: Python's exception handling
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Let's quickly review catching, prying to run code
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and then catching errors that may result
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from running that code using try except blocks.
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So, here's some code that handles two specific errors
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through a whole bunch of our program.
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We run basically the entire program
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and if ever we get a keyboard interrupt
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that's control C.
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It says let's print out hey, you're out of here
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it looks like you got a run.
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No problem, goodbye.
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And if the rolls dot JSON file is malformed
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we want to catch that error
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and say there's a problem with the rolls dot JSON file
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here are the details.
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The way we do that is we say try:
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and into that try block, we get into the block bind ending.
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We have all the stuff that we think might cause a problem
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and then we except.
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Here's one error type, except.
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Here's another error type
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and Python will automatically say
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if we encounter an exception
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we're going to go and look at the various error types
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and see which one matches.
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It's important to know
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that it's going to go down that list
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and the first one that matches
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it's going to go with that.
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So if you have a very general thing like except exception
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and then except JSON decode error
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which is also an exception
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it's like squares and rectangle sort of thing.
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It's going to stop on the first, more generic one.
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So you got to put the most specific stuff first
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and the most general stuff last.
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That's why I had that except exception as x
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at the very end of my example before.
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You can declare a variable, JE
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and use it to get more details
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or, if you don't care about that
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you don't want to do anything with the details
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just catch the exception type itself.
