Adding has_group and has_channel (#314)

nptdms/tdms.py

@@ -214,6 +214,13 @@ def __len__(self):
         """
         return len(self._groups)
 
+    def __contains__(self, group_name):
+        """ Check if TDMS file contains groupp
+
+        :rtype: Boolean
+        """
+        return group_name in self._groups
+
     def __iter__(self):
         """ Returns an iterator over the names of groups in this file
         """
@@ -355,6 +362,13 @@ def __init__(self, path, properties, channels):
     def __repr__(self):
         return "<TdmsGroup with path %s>" % self.path
 
+    def __contains__(self, channel_name):
+        """ Check if group contains channel
+
+        :rtype: Boolean
+        """
+        return channel_name in self._channels
+
     @property
     def path(self):
         """ Path to the TDMS object for this group

nptdms/test/test_tdms_file.py

@@ -899,6 +899,28 @@ def test_object_repr():
     assert repr(channel) == "<TdmsChannel with path /'Group'/'Channel1'>"
 
 
+def test_group_in_tdms_object():
+    """Test in for TDMS object
+    """
+    test_file = GeneratedFile()
+    test_file.add_segment(*basic_segment())
+    tdms_data = test_file.load()
+
+    assert 'Group' in tdms_data
+    assert 'group' not in tdms_data
+
+
+def test_channel_in_group_object():
+    """Test in for group
+    """
+    test_file = GeneratedFile()
+    test_file.add_segment(*basic_segment())
+    tdms_data = test_file.load()
+
+    assert 'Channel1' in tdms_data['Group']
+    assert 'channel1' not in tdms_data['Group']
+
+
 def test_data_read_from_bytes_io():
     """Test reading data"""