Level 3 easier but still missing necessary clues to the player.

robotgame/logic/colourboxes.py

@@ -91,14 +91,35 @@ def _get_oxs(x):
         else (x - 1, x + 1) if x % 3 == 1 \
         else (x - 2, x - 1)
 
-def generate_random_box(nwells):
-    """Generate a box with random colors except white (111)."""
+def generate_random_box(nwells, min_nonblacks=0):
+    """
+    Generate a box that triggers nwells wells, with random colors except white
+    (111).
+
+    Arguments:
+    min_nonblacks -- minimum number of well colours in a box required not to be
+    black.
+    """
     def gen_wc():
         wc = [random.choice((0, 1)) for i in range(3)]
         if all(b == 1 for b in wc):
             wc[random.randrange(3)] = 0
         return wc
-    return [tuple(gen_wc()) for _ in range(nwells)]
+    def gen_wc_nonblack():
+        wc = gen_wc()
+        if all(b == 0 for b in wc):
+            wc[random.randrange(3)] = 1
+        return wc
+    colours = [tuple(gen_wc()) for _ in range(nwells)]
+    nonblack = lambda t: any(n == 1 for n in t)
+    missing_nonblacks = min_nonblacks - len(list(filter(nonblack, colours)))
+    i = 0
+    while missing_nonblacks > 0:
+        if not nonblack(colours[i]):
+            colours[i] = gen_wc_nonblack()
+            missing_nonblacks -= 1
+        i += 1
+    return colours
 
 def get_colours(boxes):
     colours = []