Updated the doc and fixed changes according to PR thread

Author: milonimrod

intervaltree/interval.py

@@ -59,24 +59,22 @@ def overlap_size(self, begin, end=None):
         :param begin: beginning point of the range, or the point, or an Interval
         :param end: end point of the range. Optional if not testing ranges.
         :return: Return the overlap size, None if not overlap is found
-        :rtype: int
+        :rtype: depends on the given input (e.g., int will be returned for int interval and timedelta for
+        datetime intervals)
         """
         overlaps = self.overlaps(begin, end)
         if not overlaps:
-            return None
+            return 0
 
         if end is not None:
             # case end is given
             i0 = max(self.begin, begin)
             i1 = min(self.end, end)
             return i1 - i0
-        try:
-            # assume this is
-            i0 = max(self.begin, begin.begin)
-            i1 = min(self.end, begin.end)
-            return i1 - i0
-        except:
-            return 1  # case the begin is point
+        # assume the type is interval, in other cases, an exception will be thrown
+        i0 = max(self.begin, begin.begin)
+        i1 = min(self.end, begin.end)
+        return i1 - i0
 
     def contains_point(self, p):
         """

test/interval_methods/binary_test.py

@@ -62,12 +62,6 @@ def test_interval_overlap_interval():
     assert not iv0.overlaps(iv9)
 
 
-def test_interval_overlaps_size_point():
-    assert iv0.overlap_size(4) == 1
-    assert not iv0.overlap_size(19)
-    assert not iv0.overlap_size(-19)
-
-
 def test_contains_interval():
     assert iv0.contains_interval(iv0)
     assert not iv0.contains_interval(iv1)