Add 868_Binary_Gap.py (qiyuangong#23)

Added 868_Binary_Gap Python solution, by @diwansimranbanu

Author: diwansimranbanu

python/868_Binary_Gap.py

@@ -0,0 +1,14 @@
+class Solution:
+    def binaryGap(self, n: int) -> int:
+        current= 1
+        last1 = -1
+        out = 0
+        while n > 0:
+            if n%2 == 1:
+                if last1 >= 1:
+                    out = max(out, current - last1)
+                last1 = current
+            current += 1
+            n = n//2
+        return(out)
+