01_built_in_exceptions.md

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| |_) | |_| | | | ||_____| | | | \__ \
|____/ \__,_|_|_|\__|    |_|_| |_|___/

Getting to know them

Firstly, we don't really call them errors round these parts they're called exceptions. Having said that most exceptions are called "Something Error". So no one actually cares whether you call them errors or exceptions.

Python has a nice selection of built in exceptions which you can raise or catch (or cause) for just about any occasion.
A full list of the built-in exceptions can be found here.

What you are most likely to encounter are:

Exception	Cause
KeyError	No such key in dictionary
IndexError	No such index in list (or other sequence)
TypeError	Wrong object type
ValueError	Correct object type but an inappropriate value
FileNotFoundError	Tried to read a non-existent file
NotImplementedError	Tried to use something you haven't implemented
KeyboardInterrupt	Hit ctrl + c

Origin

Almost all exceptions have a common ancestor, the plain Exception class. Those that don't inherit from the Exception class are system exiting exceptions and that comes down to the way in which you can catch exceptions in general, which we'll get to in a bit.

You can both raise and catch instances of Exception but you should only catch it with great caution and you should never raise it.

Let's look at how to catch these exceptions