break into separate files

tools/testing/tests/util.py

@@ -0,0 +1,12 @@
+import math
+
+
+def shannon_entropy(data):
+    sum = 0.0
+    total = len(data)
+    for x in range(0, 256):
+        freq = data.count(x)
+        p = freq / total
+        if p > 0:
+            sum -= p * math.log2(p)
+    return sum