exception basics this part of the book deals with exceptionswhich are events that can modify the flow of control through program in pythonexceptions are triggered automatically on errorsand they can be triggered and intercepted by your code they are processed by four statements we'll study in this partthe first of which has two variations (listed separately hereand the last of which was an optional extension until python and try/except catch and recover from exceptions raised by pythonor by you try/finally perform cleanup actionswhether exceptions occur or not raise trigger an exception manually in your code assert conditionally trigger an exception in your code with/as implement context managers in python and later (optional in this topic was saved until nearly the end of the book because you need to know about classes to code exceptions of your own with few exceptions (pun intended)thoughyou'll find that exception handling is simple in python because it' integrated into the language itself as another high-level tool why use exceptionsin nutshellexceptions let us jump out of arbitrarily large chunks of program consider the hypothetical pizza-making robot we discussed earlier in the book suppose we took the idea seriously and actually built such machine to make pizzaour culinary automaton would need to execute planwhich we would implement as