  A less complex and more straightforward program is a crucial factor that
enhances its maintainability and makes writing secure and bug-free programs
easier. However, due to its heavy workload and the risks of breaking the
working programs, programmers are reluctant to do code refactoring, and thus,
it also causes the loss of potential learning experiences. To mitigate this, we
demonstrate the application of using a large language model (LLM), GPT-3.5, to
suggest less complex versions of the user-written Python program, aiming to
encourage users to learn how to write better programs. We propose a method to
leverage the prompting with few-shot examples of the LLM by selecting the
best-suited code refactoring examples for each target programming problem based
on the prior evaluation of prompting with the one-shot example. The
quantitative evaluation shows that 95.68% of programs can be refactored by
generating 10 candidates each, resulting in a 17.35% reduction in the average
cyclomatic complexity and a 25.84% decrease in the average number of lines
after filtering only generated programs that are semantically correct.
Furthermore, the qualitative evaluation shows outstanding capability in code
formatting, while unnecessary behaviors such as deleting or translating
comments are also observed.
