Merge pull request #83 from milonimrod/master

Added Interval overlap size

Author: chaimleib

intervaltree/interval.py

@@ -53,6 +53,29 @@ def overlaps(self, begin, end=None):
         except:
             return self.contains_point(begin)
 
+    def overlap_size(self, begin, end=None):
+        """
+        Return the overlap size between two intervals or a point
+        :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: 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 0
+
+        if end is not None:
+            # case end is given
+            i0 = max(self.begin, begin)
+            i1 = min(self.end, end)
+            return i1 - i0
+        # 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):
         """
         Whether the Interval contains p.

test/interval_methods/binary_test.py

@@ -36,7 +36,20 @@
 iv10 = Interval(-5, 0)
 
 
-def test_interval_overlaps_interval():
+def test_interval_overlaps_size_interval():
+    assert iv0.overlap_size(iv0) == 10
+    assert not iv0.overlap_size(iv1)
+    assert not iv0.overlap_size(iv2)
+    assert iv0.overlap_size(iv3) == 5
+    assert iv0.overlap_size(iv4) == 10
+    assert iv0.overlap_size(iv5) == 10
+    assert iv0.overlap_size(iv6) == 10
+    assert iv0.overlap_size(iv7) == 5
+    assert not iv0.overlap_size(iv8)
+    assert not iv0.overlap_size(iv9)
+
+
+def test_interval_overlap_interval():
     assert iv0.overlaps(iv0)
     assert not iv0.overlaps(iv1)
     assert not iv0.overlaps(iv2)