sudoko | Python Fiddle

def int2bit (i):
    bitmap = {
           1: 1,
           2: 2,
           3: 4,
           4: 8,
           5: 16,
           6: 32,
           7: 64,
           8: 128,
           9:256
           }
    return bitmap.get(i, 0);

def bit2int (i):
    bitmap = {
           1: 1,
           2: 2,
           4: 3,
           8: 4,
           16: 5,
           32: 6,
           64: 7,
           128: 8,
           256: 9
           }
    return bitmap.get(i, 0);

griddata = [[0 for x in range(9)] for x in range(9)] 
tdb = [[0 for x in range(9)] for x in range(9)] 
testdatay = [0 for x in range(9)]
testdatax = [0 for x in range(9)]
testdatag = [0 for x in range(9)]

gridinput = "790000300", "000006900", "800030076", "000005002", "005418700", "400700000", "610090008", "002300000", "009000054";

for y in range(9):
    for x in range(9):
        griddata[y][x] = int(gridinput[y][x]);

def printgrid():
    print "griddata\n"
    for y in range(9):
        for x in range(9):
            print (griddata[y][x]),
    	print;

def scandata():
    print "scanning table"
    for y in range(9):
        #wipe out arrays
        testdatay[y]=0;
        testdatax[y]=0;
        testdatag[y]=0;
    for y in range(9):
    	for x in range(9):
            testdatay[y]=testdatay[y]|int2bit(griddata[y][x]);
            testdatax[x]=testdatax[x]|int2bit(griddata[y][x]);
    for z in range(3):
        for w in range(3):
            for y in range(3):
                for x in range(3):
                    testdatag[(z*3)+w]=testdatag[(z*3)+w]|int2bit(griddata[y+(z*3)][x+(w*3)]);
                                                    
#9bits = 511 decimal
t=0;
tcomp=0;
solveone=1;
for loop in range(99):
    print;
    print "Scan: ",loop;
    scandata();
    printgrid();
    solveone=0;
    for y in range(9):
        for x in range(9):
            #print x,y,
            t=testdatax[x]|testdatay[y]|testdatag[(y/3)*3+(x/3)]
            tcomp=511^t
            tdb[y][x]=t;
            #print "y,x,gd, gdb, ,t:",y,x,griddata[y][x],bin(int2bit(griddata[y][x])),bin(tcomp)
            if((griddata[y][x] == 0) and (bit2int(tcomp) > 0)):
                griddata[y][x]=bit2int(tcomp);
                solveone=1;
                print "solved single: ", y, x, bit2int(tcomp);
    #end yx loop
    #need to scan in 3s
    for y in range(9):
        for x in range(9):
            ta=tdb[y][x];
            for i in range(9):
                if i <> x:
                    ta=ta ^ tdb[y][i];
            if((griddata[y][x] == 0 ) and (bit2int(ta) > 0)):
                griddata[y][x] = bit2int(ta);
                solveone=1;
                print "solved exclusive: ", y, x, bin(tx);
                 
    if solveone>0:
        print "one or more solved"
    else:
        break

print "finished"
printgrid();

Python Fiddle

Python Cloud IDE