Parsons

A working program → a worksheet of shuffled blocks to put back in order, with optional distractors, and a key.

• Split at Statements (compound headers and their bodies become separate blocks, so structure is rebuilt too) or Lines.
• Distractors are real lines with one mistake a pupil can spot from the sheet: a colon removed, a comparison changed (< to <=, == to !=…; the key says wrong comparison), a number off by one in a range(), an index or a while condition, or a wrong variable. A wrong variable is another of the program's own variables of the same sort, already set when the line runs (total = total + count for total = total + score), never a list for a number or a name the line could not use yet. Data is never changed: list values, a variable's starting value, the number in an if and strings stay as written, and no distractor adds + 0. A program with none of these gets fewer distractors than asked for. The key says which blocks to leave out, the real line each one looks like, and what is wrong with it.
• Show indentation off makes pupils decide the indents.
• Include a hint box (on by default) prints a short starting hint above the blocks.
• The sheet prints the blocks as numbered cut-out boxes, two across, with dashed cut lines and an answer grid underneath; a 15-block problem fits on one A4 page.
• The key reconstructs the program; the tests prove it is equivalent to the input.
• The seed is in the file name and on the sheet, so the same shuffle can be made again.

Files: <stem>_parsons_s<seed>.docx / .pdf and …_key (Outputs). Parsons problem, distractor and seed are in the Glossary.

staff parsons make program.py --seed 7 --distractors 2 [--lines] [--no-indent]