Python for Absolute Beginners Transcripts
Chapter: Error handling
Lecture: Concept: Python's exception handling
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0:00
Let's quickly review catching, prying to run code and then catching errors that may result from running that code using try except blocks.
0:09
So, here's some code that handles two specific errors through a whole bunch of our program. We run basically the entire program
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and if ever we get a keyboard interrupt that's control C. It says let's print out hey, you're out of here it looks like you got a run.
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No problem, goodbye. And if the rolls dot JSON file is malformed we want to catch that error and say there's a problem with the rolls dot JSON file
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here are the details. The way we do that is we say try: 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 and then we except. Here's one error type, except. Here's another error type
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and Python will automatically say if we encounter an exception we're going to go and look at the various error types and see which one matches.
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It's important to know that it's going to go down that list and the first one that matches it's going to go with that.
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So if you have a very general thing like except exception and then except JSON decode error which is also an exception
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it's like squares and rectangle sort of thing. It's going to stop on the first, more generic one. So you got to put the most specific stuff first
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and the most general stuff last. That's why I had that except exception as x at the very end of my example before. You can declare a variable, JE
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and use it to get more details or, if you don't care about that you don't want to do anything with the details just catch the exception type itself.