port of PYSWIP package.

packages/pyswip/examples/sudoku/sudoku_daily.py

@@ -0,0 +1,78 @@
+# -*- coding: utf-8 -*-
+
+# Sudoku auto-solver. Get today's sudoku at http://www.sudoku.org.uk/daily.asp
+# and solve it
+
+import urllib
+from HTMLParser import HTMLParser, HTMLParseError
+from pyswip.prolog import Prolog
+from pyswip.easy import *
+
+URL = "http://www.sudoku.org.uk/daily.asp"
+
+class DailySudokuPuzzle(HTMLParser):
+    def __init__(self):
+        self.puzzle = []
+        self.__in_td = False
+        HTMLParser.__init__(self)
+        
+    def handle_starttag(self, tag, attrs):
+        if tag == "td":
+            for attr in attrs:
+                if attr[0] == "class" and attr[1] == "InnerTDone":
+                    self.__in_td = True
+                    break
+        elif tag == "input":
+            if self.__in_td:
+                self.puzzle.append(0)
+                
+    def handle_endtag(self, tag):
+        if tag == "td":
+            self.__in_td = False
+            
+    def handle_data(self, data):
+        if self.__in_td:
+            self.puzzle.append(int(data))        
+
+def pretty_print(table):
+    print "".join(["/---", "----"*8, "\\"])
+    for row in table:
+        print "".join(["|", "|".join(" %s " % (i or " ") for i in row), "|"])
+    print "".join(["\\---", "----"*8, "/"])        
+
+def get_daily_sudoku(url):
+    puzzle = DailySudokuPuzzle()
+    f = urllib.urlopen(url)
+    try:
+        puzzle.feed(f.read())
+    except HTMLParseError:
+        pass
+    puzzle = puzzle.puzzle
+    return [puzzle[i*9:i*9+9] for i in range(9)]
+
+def solve(problem):
+    prolog.consult("sudoku.pl")
+    p = str(problem).replace("0", "_")
+    result = list(prolog.query("Puzzle=%s,sudoku(Puzzle)" % p, maxresult=1))
+    if result:
+        result = result[0]
+        return result["Puzzle"]
+    else:
+        return False    
+    
+if __name__ == "__main__":
+    prolog = Prolog()  # having this in `solve` bites! because of __del__
+    
+    print "Getting puzzle from:", URL
+    
+    puzzle = get_daily_sudoku(URL)
+    print "-- PUZZLE --"
+    pretty_print(puzzle)    
+    print
+    print " -- SOLUTION --"
+    solution = solve(puzzle)
+    if solution:
+        pretty_print(solution)
+    else:
+        print "This puzzle has no solutions [is it valid?]"
+