learnings.md

Things I learned

• Python's isinstance() function can be used to check the type of an object.
  • It was useful for turning ints into lists for comparisons
• Python's sorted() function can sort using a custom comparison function.
  • It was useful for reusing the already made, custom compare() function from part 1 to sort all the packets for part 2.
  • Allowed me to remove the quicksort implementation I had originally.
• You can use cmp_to_key() from the functools library to use your custom comparison function to generate keys for the sorted() function above.
• It's often useful for a comparison function to return one of three values (positive, 0 ,negative) instead of just true or false.
  • This was useful when the compared items inside of a recursion were equal to each other and I wanted to continue iterating out of the recursion and not just bubble up true or false.
  • Relating to the above, originally I tried returning true when left <= right, but then when I bubbled out of the recursion, it was ambiguous whether the returned true was because left < right or left == right. The distinction was important for logic flow afterwards.