Saving and loading puzzles¶

A puzzle holds a genre’s clues. Every puzzle has:

Attribute	Value
`genre`	The genre name, such as `"sudoku"`
`shape`	`(rows, columns)`
`id`	A one-line ID that holds the whole puzzle
`clues`	The clues, in a form that depends on the genre

Puzzles are immutable and compare equal when their clues are equal.

Clues by genre¶

Each genre has its own puzzle class:

Class	`clues`
`SudokuPuzzle`	Rows of digits, 0 for an empty cell
`NurikabePuzzle`, `FillominoPuzzle`	Rows of numbers, 0 for an empty cell
`HashiPuzzle`	Rows of island numbers, 0 for an empty cell
`HitoriPuzzle`	Rows of numbers
`KakuroPuzzle`	Rows of cells: `None` for a white cell, `(down, across)` for a block, 0 for a missing sum
`KakurasuPuzzle`	A `KakurasuClues` with `rows` and `cols`

>>> g = pp.generate("kakuro", (6, 6), difficulty="easy", seed=4)
>>> g.puzzle.clues[1]
((0, 0), (0, 15), None, None, (12, 0), (16, 0))

Printing¶

print(puzzle) shows the grid laid out for reading:

>>> print(g.puzzle)
   #    #  25/   7/    #    #
   #  /15    .    .  12/  16/
   # 3/13    .    .    .    .
  /7    .    . 3/13    .    .
 /15    .    .    .    .    #
   #    #   /3    .    .    #

IDs¶

The ID is the shortest way to store or share a puzzle. It starts with the genre and size:

>>> pp.generate("sudoku", (4, 4), difficulty="easy", seed=1).puzzle.id
'sudoku:4x4:31............34'
>>> puzzle = pp.Puzzle.from_id('sudoku:4x4:31............34')

Puzzle.from_id returns the genre’s puzzle class. The web app accepts the same IDs: https://pencil-puzzles.org/sudoku/player/?puzzle=<ID> opens the puzzle there.

Text format¶

to_text() gives a text form that is easy to read and edit, and Puzzle.from_text() reads it back:

>>> print(puzzle.to_text())
genre: sudoku
grid:
31..
....
....
..34

You can write puzzles in this format by hand, for example to solve or rate a puzzle from a book. Each genre page describes its format under Formats.

from_id and from_text raise ParseError when the input cannot be read.