add initial Map and Tile classes

Map.py

@@ -0,0 +1,22 @@
+
+# odd-numbered rows are right-shifted by half a tile width
+class Map(object):
+    def __init__(self):
+        self._arr = []
+
+    def add(self, row, col, tile):
+        self._extend(row, col)
+        self._arr[row][col] = tile
+
+    def get(self, row, col):
+        if len(self._arr) <= row:
+            return None
+        if len(self._arr[row]) <= col:
+            return None
+        return self._arr[row][col]
+
+    def _extend(self, row, col):
+        while len(self._arr) <= row:
+            self._arr.append([])
+        while len(self._arr[row]) <= col:
+            self._arr[row].append(None)

Tile.py

@@ -0,0 +1,5 @@
+
+class Tile(object):
+    def __init__(self, typ, roll_val):
+        self.type = typ
+        self.roll_val = roll_val