Quill & Quotient

Quill & QuotientExplainers

Explainers

Short reads, one idea each

Explainers on the parts of programming that trip up first and second-year students: indexes, tracebacks, reading unfamiliar code. Each one takes a single idea and stops.

  1. Why your loop runs one time too many

    Fig.

    Debugging

    Why your loop runs one time too many

    Off-by-one errors come from counting the boundary rather than the elements. A short walk through zero-indexed lists shows where the extra pass comes from.

    6 min read

  2. What a traceback is actually telling you

    Fig.

    Basics

    What a traceback is actually telling you

    The report Python prints when something fails is a list of calls, not a verdict. Read it from the bottom up and the failing line appears quickly.

    5 min read

  3. How to read code you did not write

    Fig.

    Study

    How to read code you did not write

    A repository you have never seen is hard to enter at the top. Find the entry point, follow one value, and the map starts to draw itself.

    7 min read

  4. Pair programming without copying the answer

    Fig.

    Study

    Pair programming without copying the answer

    Two people, one problem, one keyboard. What pairing teaches is the sentence you have to say out loud before you can defend a line of code.

    6 min read

  5. Building a revision plan for a coding exam

    Fig.

    Exams

    Building a revision plan for a coding exam

    Rereading notes is the wrong exercise for a coding exam. Short timed blocks, a list of your own faults and a rehearsal under exam conditions do more.

    8 min read