Add __eq__ method to SigMFFile (#98)

Author: Teque5

sigmf/sigmffile.py

@@ -192,6 +192,17 @@ def __init__(self, metadata=None, data_file=None, global_info=None, skip_checksu
     def __len__(self):
         return self._memmap.shape[0]
 
+    def __eq__(self, other):
+        """
+        Define equality between two `SigMFFile`s.
+
+        Rely on the checksum value in the metadata to decide whether `data_file` is the same since the path of the
+        dataset is immaterial to equivalency.
+        """
+        if isinstance(other, SigMFFile):
+            return self._metadata == other._metadata
+        return False
+
     def __next__(self):
         """get next batch of samples"""
         if self.iter_position < len(self):

tests/test_sigmffile.py

@@ -59,6 +59,14 @@ def test_checksum(self):
             with self.assertRaises(error.SigMFFileError):
                 _ = SigMFFile(bad_checksum_metadata, self.temp_path_data)
 
+    def test_equality(self):
+        """Ensure __eq__ working as expected"""
+        other = SigMFFile(copy.deepcopy(TEST_METADATA))
+        self.assertEqual(self.sigmf_object, other)
+        # different after changing any part of metadata
+        other.add_annotation(start_index=0, metadata={"a": 0})
+        self.assertNotEqual(self.sigmf_object, other)
+
 
 class TestAnnotationHandling(unittest.TestCase):
     def test_get_annotations_with_index(self):