Color-code SQL: code review changes; fallback to black after 2**24 colors

1 files changed, 6 insertions, 4 deletions

diff --git a/debug_toolbar/panels/sql/utils.py b/debug_toolbar/panels/sql/utils.py
index d6f0173..65d26bd 100644
--- a/debug_toolbar/panels/sql/utils.py
+++ b/debug_toolbar/panels/sql/utils.py
@@ -40,20 +40,22 @@ def swap_fields(sql):
 def contrasting_color_generator():
     """
     Generate constrasting colors by varying most significant bit of RGB first,
-    and then vary subsebequent bits systematically.
+    and then vary subsequent bits systematically.
     """
     def rgb_to_hex(rgb):
         return '#%02x%02x%02x' % tuple(rgb)
 
     triples = [(1, 0, 0), (0, 1, 0), (0, 0, 1),
                (1, 1, 0), (0, 1, 1), (1, 0, 1), (1, 1, 1)]
-    n = 128
+    n = 1 << 7
     so_far = [[0, 0, 0]]
-    while (1):
+    while True:
+        if n == 0:  # This happens after 2**24 colours; presumably, never
+            yield "#000000"  # black
         copy_so_far = list(so_far)
         for triple in triples:
             for previous in copy_so_far:
                 rgb = [n * triple[i] + previous[i] for i in range(3)]
                 so_far.append(rgb)
                 yield rgb_to_hex(rgb)
-        n = n / 2
+        n >>= 1