Catching exceptions with try / except

20-minute lesson · module-exceptions-03

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Catching exceptions with try / except

20-minute lesson · module-exceptions-03

  • Write a try/except block to handle a runtime error without crashing.
  • Catch a specific exception type rather than everything.
  • Use the else clause for code that should run only when no exception occurred.
  • Bind the exception object with `as` to inspect its message.

Source attribution

Status: adapted

How to Think Like a Computer Scientist: Interactive Edition source · Exceptions / Handling exceptions with try/except

Adaptation notes. Reading rewritten in our voice. The worked example safely parses user-entered credit hours in an Iowa State enrollment theme. Hidden tests check that a function recovers from bad input and returns a sentinel rather than raising, and that it catches a specific type.

License notes. Original chapter is GNU FDL 1.3 (Brad Miller and David Ranum). No verbatim text from the original is reproduced here.