Update insert-interval.py

Author: kamyu104

Python/insert-interval.py

@@ -31,11 +31,11 @@ def insert(self, intervals, newInterval):
         return self.merge(intervals + [newInterval])
 
     def merge(self, intervals):
-        if len(intervals) == 0:
+        if not intervals:
             return intervals
         intervals.sort(key = lambda x: x.start)
         result = [intervals[0]]
-        for i in range(1, len(intervals)):
+        for i in xrange(1, len(intervals)):
             prev, current = result[-1], intervals[i]
             if current.start <= prev.end: 
                 prev.end = max(prev.end, current.end)
@@ -44,4 +44,4 @@ def merge(self, intervals):
         return result
 
 if __name__ == "__main__":
-    print Solution().insert([Interval(1, 2), Interval(3, 5), Interval(6, 7), Interval(8, 10), Interval(12, 16)], Interval(4, 9))
+    print Solution().insert([Interval(1, 2), Interval(3, 5), Interval(6, 7), Interval(8, 10), Interval(12, 16)], Interval(4, 9))