Solutions & Walkthroughs

Each solution introduces some new aspect of programming, or takes an existing idea further. Hopefully there's something new here for everyone, even if you've already solved the puzzles.

Dec 1 - Abstract *

• Is a 'space' a character? 

• ASCII vs Unicode

Dec 2 - Sub-zero *

• Edge cases

• Looping with list comprehensions

• Sub-functions

• Checking expectations with assert

Dec 3 - Who's nice *

• Colab shortcut keys

• Test-driven development (TDD)

Dec 4 - How nice? *

• More Colab shortcut keys

• Five ways to convert a float number to an int 

Dec 5 - Just 5 *

• Even more Colab shortcut keys

• Type hints in function definitions

• Refactoring functions

• List comprehension with an if filter

Dec 6 - Crackers **

• Code folding

• Tuple assignment & chained comparisons

• More list comprehensions

Dec 7 - Cryptic CHRs *

• Letters as numbers & the ASCII table, using chr and ord

• The Accumulator Pattern

• Even more list comprehensions!

Dec 8 - to4ys **

Dec 9 - Journey **

• Type hints & type checking

• More of unit testing using assert

Dec 10 - Chimneys ***

• The dict collection type

Dec 11 - Bingo **

• Using an array's .count method

• Using zip to get pairs of items from two lists

• Using enumerate to get the loop number

• Passing a 'noisy' True/False parameter to turn print messages off

Dec 12 - Christmas bits * 

Dec 13 - Stables ***

Dec 14 - Sleigh ride ***

Dec 15 - 1 star *

Dec 16 - Patches ***