Examples

Sudoku

Sudoku example

You can run this module using:

$ python3 -m pyswip.examples.sudoku

class pyswip.examples.sudoku.Matrix(matrix)

Represents a 9x9 Sudoku puzzle

classmethod from_text(text)

Create a Matrix from the given string

The following are valid characters in the string:

• .: Blank column

• 1-9: Numbers

The text must contain exactly 9 rows and 9 columns. Each row ends with a newline character. You can use blank lines and spaces/tabs between columns.

Parameters:

text (str) – The text to use for creating the Matrix

Return type:

Matrix

>>> puzzle = Matrix.from_text('''
... . . 5 . 7 . 2 6 8
... . . 4 . . 2 . . .
... . . 1 . 9 . . . .
... . 8 . . . . 1 . .
... . 2 . 9 . . . 7 .
... . . 6 . . . . 3 .
... . . 2 . 4 . 7 . .
... . . . 5 . . 9 . .
... 9 5 7 . 3 . . . .
... ''')

pretty_print(*, file=None)

Prints the matrix as a grid

Parameters:

file (Optional[IO]) – The file to use for printing

Return type:

None

>>> import sys
>>> puzzle = sample_puzzle()
>>> puzzle.pretty_print(file=sys.stdout)
. . 5 . 7 . 2 6 8
. . 4 . . 2 . . .
. . 1 . 9 . . . .
. 8 . . . . 1 . .
. 2 . 9 . . . 7 .
. . 6 . . . . 3 .
. . 2 . 4 . 7 . .
. . . 5 . . 9 . .
9 5 7 . 3 . . . .

pyswip.examples.sudoku.prolog_source()

Returns the Prolog source file that solves Sudoku puzzles.

Return type:

str

pyswip.examples.sudoku.sample_puzzle()

Returns the sample Sudoku puzzle

Return type:

Matrix

pyswip.examples.sudoku.solve(matrix)

Solves the given Sudoku puzzle

Parameters:

matrix (Matrix) – The matrix that contains the Sudoku puzzle

Return type:

Union[Matrix, Literal[False]]

>>> puzzle = sample_puzzle()
>>> print(puzzle)
. . 5 . 7 . 2 6 8
. . 4 . . 2 . . .
. . 1 . 9 . . . .
. 8 . . . . 1 . .
. 2 . 9 . . . 7 .
. . 6 . . . . 3 .
. . 2 . 4 . 7 . .
. . . 5 . . 9 . .
9 5 7 . 3 . . . .

>>> print(solve(puzzle))
3 9 5 4 7 1 2 6 8
8 7 4 6 5 2 3 9 1
2 6 1 3 9 8 5 4 7
5 8 9 7 6 3 1 2 4
1 2 3 9 8 4 6 7 5
7 4 6 2 1 5 8 3 9
6 1 2 8 4 9 7 5 3
4 3 8 5 2 7 9 1 6
9 5 7 1 3 6 4 8 2

Hanoi

pyswip.examples.hanoi.solve(disk_count=3, simple=False, file=None)

Solves the Towers of Hanoi problem.

Parameters:

• disk_count (int) – Number of disks to use

• simple (bool) – If set to True, only the moves are printed. Otherwise all states are drawn.

• file (IO) – The file-like object to output the steps of the solution. By default stdout is used.

Return type:

None

>>> solve(3, simple=True)
1. Move disk from left pole to right pole.
2. Move disk from left pole to center pole.
3. Move disk from right pole to center pole.
4. Move disk from left pole to right pole.
5. Move disk from center pole to left pole.
6. Move disk from center pole to right pole.
7. Move disk from left pole to right pole.

pyswip.examples.hanoi.prolog_source()

Returns the Prolog source file that solves the Towers of Hanoi problem.

Return type:

str

Coins

pyswip.examples.coins.solve(*, coin_count=100, total_cents=500, max_solutions=1)

Solves the coins problem.

Finds and returns combinations of coin_count coins that makes total cents.

Parameters:

• coin_count (int) – Number of coins

• total_cents (int) – Total cent value of coins

Return type:

List[Dict[int, int]]

pyswip.examples.coins.prolog_source()

Returns the Prolog source file that solves the coins problem.

Return type:

str