I'd like to translate this code into Python. Do you know if these instructions will translate one-to-one?

In other words, does Python have language features which translate one-to-one with C features?

Does Python have bitwise operators, and assignment operators (like XOR)?

I'm using this exercise as an opportunity to learn some Python :-)

#include <stdio.h> #include <stdlib.h> #define GRIDSIZE 9 #define MAXLINE GRIDSIZE+2 unsigned int grid[GRIDSIZE][GRIDSIZE]; unsigned int col[GRIDSIZE]; unsigned int row[GRIDSIZE]; unsigned int region[GRIDSIZE]; unsigned int istack[GRIDSIZE*GRIDSIZE]; unsigned int jstack[GRIDSIZE*GRIDSIZE]; unsigned int stackp; void grid_input(char *filename); void grid_display(); void placenum(unsigned n, unsigned i, unsigned j); void removenum(unsigned n, unsigned i, unsigned j); unsigned solve(); unsigned legal(unsigned n, unsigned i, unsigned j); main(int argc, char **argv) { grid_input(argv[1]); grid_display(); if (solve()) { printf("Solution found!\n"); grid_display(); } else { printf("No solution found\n"); } exit(0); } /* read initial grid from specified file */ void grid_input(char *filename) { FILE *fp; char line[MAXLINE]; unsigned i,j; if ((fp = fopen(filename, "r")) == NULL) { fprintf(stderr, "Couldn't open input file\n"); exit(1); } stackp = 0; for (i = 0; i < GRIDSIZE; i++) { if (fgets(line, MAXLINE, fp)) { for (j = 0; j < GRIDSIZE; j++) { if (line[j] >= '1' && line[j] <= '9') { placenum(line[j] - '0', i, j); } else { /* assume empty */ istack[stackp] = i; jstack[stackp] = j; stackp++; } } } else { fprintf(stderr, "Unexpected input error\n"); exit(1); } } } /* solve grid with current stack of empty squares */ unsigned solve() { int n; int i, j; if (stackp <= 0) { /* no empty squares so */ return 1; /* solved */ } stackp--; i = istack[stackp]; j = jstack[stackp]; for (n = 1; n <= 9; n++) { if (legal(n, i, j)) { placenum(n, i, j); if (solve()) { return 1; } removenum(n, i, j); } } /* no solution at all from this point */ stackp++; return 0; } /* is it legal to put value n at row i, column j? */ unsigned legal(unsigned n, unsigned i, unsigned j) { return (grid[i][j] == 0) && ((row[i] & (1 << (n-1))) == 0) && ((col[j] & (1 << (n-1))) == 0) && ((region[3 * (i/3) + (j/3)] & (1 << (n-1))) == 0); } /* place number n at row i, column j */ void placenum(unsigned n, unsigned i, unsigned j) { unsigned r; grid[i][j] = n; row[i] ^= (1 << (n-1)); col[j] ^= (1 << (n-1)); region[3 * (i/3) + (j/3)] ^= (1 << (n-1)); } /* remove number n at row i, column j */ void removenum(unsigned n, unsigned i, unsigned j) { unsigned r; grid[i][j] = 0; row[i] ^= (1 << (n-1)); col[j] ^= (1 << (n-1)); region[3 * (i/3) + (j/3)] ^= (1 << (n-1)); } /* display current grid */ void grid_display() { unsigned i, j; for (i = 0; i < GRIDSIZE; i++) { for (j = 0; j < GRIDSIZE; j++) { printf("+---"); } printf("+\n"); for (j = 0; j < GRIDSIZE; j++) { if (grid[i][j] == 0) { printf("| "); } else { printf("| %d ", grid[i][j]); } } printf("|\n"); } for (j = 0; j < GRIDSIZE; j++) { printf("+---"); } printf("+\n"); }