Python Programming

We then turned to more advanced, Python-specific topics relating to functions. Here are some questions to ponder.

• How do you use the built-in any() and all() functions? How do they relate to the and and or operators?
• How can you make a Python function receive an arbitrary number of positional arguments?
• How can you have a Python function receive an arbitrary number of keyword arguments?
• How do you force a function to receive keyword-only arguments? What about position-only arguments?
• What are lambda functions?
• When will a lambda function be useful compared to a traditional function defined with the def keyword?
• How do you use lambda functions in the sorted(), min() and max() functions, as well as the list.sort() method?
• What are higher-order functions?
• Name two example higher-order functions that come built-in with Python. Do you know how to use these functions?
• Do you know how to use lambda functions with these higher-order functions?
• Are you able to write the list comprehension equivalent of these higher-order functions?

We also looked at using the unittest module for easier automated testing. You can easily run multiple test cases, provide more informative assertion error messages, and set up text fixtures.

Finally, we ended the lesson by going back to our main topic (inheritance), as applied to exception handling. If the built-in Python Exceptions do not fulfil your need, you can create your custom errors by extending the Exception class. The class is like any other class, so you can define more attributes/methods as you see fit. Beware of the order of catching the exceptions if your class is a more specific subclass!