Merge pull request #349 from Daimler/encode_decoded

cantools/database/can/signal.py

@@ -115,10 +115,10 @@ def comments(self):
         return self._comments
 
     def __str__(self):
-        return self._name
+        return f"{self._name}"
 
     def __repr__(self):
-        return f"{self._name}"
+        return f"'{self._name}'"
 
     def __eq__(self, x):
         if isinstance(x, NamedSignalValue):

cantools/database/utils.py

@@ -3,6 +3,7 @@
 import binascii
 from decimal import Decimal
 from collections import namedtuple
+from cantools.database.can.signal import NamedSignalValue
 
 try:
     import bitstruct.c
@@ -50,6 +51,8 @@ def _encode_field(field, data, scaling):
 
     if isinstance(value, str):
         return field.choice_string_to_number(value)
+    elif isinstance(value, NamedSignalValue):
+        return field.choice_string_to_number(str(value))
     elif scaling:
         if field.is_float:
             return (value - field.offset) / field.scale

tests/test_database.py

@@ -506,6 +506,11 @@ def test_motohawk_encode_decode(self):
                                         decode_choices=False)
             self.assertEqual(decoded, decoded_message)
 
+            # check that encode(decode(encode(decoded))) == encode(decoded)
+            encoded2 = db.encode_message(example_message_frame_id, decoded)
+            self.assertEqual(encoded2, encoded)
+
+
         # Encode with enumerated values.
         decoded_message = {
             'Temperature': 250.55,
@@ -520,6 +525,10 @@ def test_motohawk_encode_decode(self):
         decoded = db.decode_message(example_message_frame_id, encoded)
         self.assertEqual(decoded, decoded_message)
 
+        # check that encode(decode(data)) == data
+        encoded2 = db.encode_message(example_message_frame_id, decoded)
+        self.assertEqual(encoded2, encoded)
+
         # By name.
         encoded = db.encode_message(example_message_name, decoded_message)
         self.assertEqual(encoded, encoded_message)