Decorators are great for adding common functionality to several functions without duplicating code. For example, I have one for my IRC bot that checks that the person sending the command is authorized to use the command. It's only "if mask in owner list then execute function else say access denied", but it simplifies the code and the intent of each function that uses it becomes more obvious. I have another that puts functions in a common try/except clause, which again simplifies the functions and makes them easier to understand.
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