Add back PdoBase.export() dependency (canmatrix) (#493)

The canmatrix optional dependency was removed on Oct 10, 2021 with commit
c46228f. It is now added back as an optional dependency, using the same
name as previously: db_export.

To install the dependency:

$ python3 -m pip install 'canopen[db_export]'

Resolves #488

Author: erlend-aasland

.github/workflows/pythonpackage.yml

@@ -17,6 +17,7 @@ jobs:
       fail-fast: false
       matrix:
         python-version: ['3.x']
+        features: ['', '[db_export]']
 
     steps:
     - uses: actions/checkout@v3
@@ -28,7 +29,7 @@ jobs:
       run: |
         python -m pip install --upgrade pip
         pip install pytest pytest-cov
-        pip install -e .
+        pip install -e '.${{ matrix.features }}'
     - name: Test with pytest
       run: |
         pytest -v --cov=canopen --cov-report=xml --cov-branch

canopen/pdo/base.py

@@ -78,14 +78,24 @@ def subscribe(self):
     def export(self, filename):
         """Export current configuration to a database file.
 
+        .. note::
+           This API requires the ``db_export`` feature to be installed::
+
+              python3 -m pip install 'canopen[db_export]'
+
         :param str filename:
             Filename to save to (e.g. DBC, DBF, ARXML, KCD etc)
+        :raises NotImplementedError:
+            When the ``canopen[db_export]`` feature is not installed.
 
         :return: The CanMatrix object created
         :rtype: canmatrix.canmatrix.CanMatrix
         """
-        from canmatrix import canmatrix
-        from canmatrix import formats
+        try:
+            from canmatrix import canmatrix
+            from canmatrix import formats
+        except ImportError:
+            raise NotImplementedError("This feature requires the 'canopen[db_export]' feature")
 
         db = canmatrix.CanMatrix()
         for pdo_map in self.map.values():

pyproject.toml

@@ -26,6 +26,11 @@ dependencies = [
 ]
 dynamic = ["version"]
 
+[project.optional-dependencies]
+db_export = [
+    "canmatrix ~= 1.0",
+]
+
 [project.urls]
 documentation = "https://canopen.readthedocs.io/en/stable/"
 repository = "https://github.com/christiansandberg/canopen"

test/test_pdo.py

@@ -5,36 +5,41 @@
 
 
 class TestPDO(unittest.TestCase):
-
-    def test_bit_mapping(self):
+    def setUp(self):
         node = canopen.Node(1, SAMPLE_EDS)
-        map = node.pdo.tx[1]
-        map.add_variable('INTEGER16 value')  # 0x2001
-        map.add_variable('UNSIGNED8 value', length=4)  # 0x2002
-        map.add_variable('INTEGER8 value', length=4)  # 0x2003
-        map.add_variable('INTEGER32 value')  # 0x2004
-        map.add_variable('BOOLEAN value', length=1)  # 0x2005
-        map.add_variable('BOOLEAN value 2', length=1)  # 0x2006
+        pdo = node.pdo.tx[1]
+        pdo.add_variable('INTEGER16 value')  # 0x2001
+        pdo.add_variable('UNSIGNED8 value', length=4)  # 0x2002
+        pdo.add_variable('INTEGER8 value', length=4)  # 0x2003
+        pdo.add_variable('INTEGER32 value')  # 0x2004
+        pdo.add_variable('BOOLEAN value', length=1)  # 0x2005
+        pdo.add_variable('BOOLEAN value 2', length=1)  # 0x2006
 
         # Write some values
-        map['INTEGER16 value'].raw = -3
-        map['UNSIGNED8 value'].raw = 0xf
-        map['INTEGER8 value'].raw = -2
-        map['INTEGER32 value'].raw = 0x01020304
-        map['BOOLEAN value'].raw = False
-        map['BOOLEAN value 2'].raw = True
+        pdo['INTEGER16 value'].raw = -3
+        pdo['UNSIGNED8 value'].raw = 0xf
+        pdo['INTEGER8 value'].raw = -2
+        pdo['INTEGER32 value'].raw = 0x01020304
+        pdo['BOOLEAN value'].raw = False
+        pdo['BOOLEAN value 2'].raw = True
+
+        self.pdo = pdo
+        self.node = node
 
-        # Check expected data
-        self.assertEqual(map.data, b'\xfd\xff\xef\x04\x03\x02\x01\x02')
+    def test_pdo_map_bit_mapping(self):
+        self.assertEqual(self.pdo.data, b'\xfd\xff\xef\x04\x03\x02\x01\x02')
 
-        # Read values from data
-        self.assertEqual(map['INTEGER16 value'].raw, -3)
-        self.assertEqual(map['UNSIGNED8 value'].raw, 0xf)
-        self.assertEqual(map['INTEGER8 value'].raw, -2)
-        self.assertEqual(map['INTEGER32 value'].raw, 0x01020304)
-        self.assertEqual(map['BOOLEAN value'].raw, False)
-        self.assertEqual(map['BOOLEAN value 2'].raw, True)
+    def test_pdo_map_getitem(self):
+        pdo = self.pdo
+        self.assertEqual(pdo['INTEGER16 value'].raw, -3)
+        self.assertEqual(pdo['UNSIGNED8 value'].raw, 0xf)
+        self.assertEqual(pdo['INTEGER8 value'].raw, -2)
+        self.assertEqual(pdo['INTEGER32 value'].raw, 0x01020304)
+        self.assertEqual(pdo['BOOLEAN value'].raw, False)
+        self.assertEqual(pdo['BOOLEAN value 2'].raw, True)
 
+    def test_pdo_getitem(self):
+        node = self.node
         self.assertEqual(node.tpdo[1]['INTEGER16 value'].raw, -3)
         self.assertEqual(node.tpdo[1]['UNSIGNED8 value'].raw, 0xf)
         self.assertEqual(node.tpdo[1]['INTEGER8 value'].raw, -2)
@@ -54,10 +59,26 @@ def test_bit_mapping(self):
         self.assertEqual(node.tpdo[0x2002].raw, 0xf)
         self.assertEqual(node.pdo[0x1600][0x2002].raw, 0xf)
 
-    def test_save_pdo(self):
-        node = canopen.Node(1, SAMPLE_EDS)
-        node.tpdo.save()
-        node.rpdo.save()
+    def test_pdo_save(self):
+        self.node.tpdo.save()
+        self.node.rpdo.save()
+
+    def test_pdo_export(self):
+        import tempfile
+        try:
+            import canmatrix
+        except ImportError:
+            raise unittest.SkipTest("The PDO export API requires canmatrix")
+
+        for pdo in "tpdo", "rpdo":
+            with tempfile.NamedTemporaryFile(suffix=".csv") as tmp:
+                fn = tmp.name
+                with self.subTest(filename=fn, pdo=pdo):
+                    getattr(self.node, pdo).export(fn)
+                    with open(fn) as csv:
+                        header = csv.readline()
+                        self.assertIn("ID", header)
+                        self.assertIn("Frame Name", header)
 
 
 if __name__ == "__main__":