Wrap all open() calls in a context manager

malcolm/modules/ADCore/parts/hdfwriterpart.py

@@ -136,7 +136,8 @@ def configure(self, context, completed_steps, steps_to_do, part_info, params):
         xml = self._make_layout_xml(params.generator, part_info)
         self.layout_filename = os.path.join(
             file_dir, "%s-layout.xml" % self.params.mri)
-        open(self.layout_filename, "w").write(xml)
+        with open(self.layout_filename, "w") as f:
+            f.write(xml)
         # We want the HDF writer to flush this often:
         flush_time = 1  # seconds
         # (In particular this means that HDF files can be read cleanly by

malcolm/modules/ADCore/parts/statspluginpart.py

@@ -64,7 +64,8 @@ def configure(self, context, completed_steps, steps_to_do, part_info,
         xml = self._make_attributes_xml()
         self.attributes_filename = os.path.join(
             params.fileDir, "%s-attributes.xml" % self.params.mri)
-        open(self.attributes_filename, "w").write(xml)
+        with open(self.attributes_filename, "w") as f:
+            f.write(xml)
         fs.append(
             child.attributesFile.put_value_async(self.attributes_filename))
         context.wait_all_futures(fs)

malcolm/modules/builtin/controllers/managercontroller.py

@@ -402,7 +402,8 @@ def do_save(self, design=""):
             structure[part_name] = part_structure
         text = json_encode(structure, indent=2)
         filename = self._validated_config_filename(design)
-        open(filename, "w").write(text)
+        with open(filename, "w") as f:
+            f.write(text)
         self._mark_clean(design)
 
     def _set_layout_names(self, extra_name=None):
@@ -445,7 +446,8 @@ def set_design(self, value):
 
     def do_load(self, design):
         filename = self._validated_config_filename(design)
-        text = open(filename, "r").read()
+        with open(filename, "r") as f:
+            text = f.read()
         structure = json_decode(text)
         # Set the layout table
         layout_table = Table(self.layout.meta)

tests/test_modules/test_ADCore/test_hdfwriterpart.py

@@ -222,7 +222,8 @@ def test_configure(self):
 </group>
 </group>
 </hdf5_layout>"""
-        actual_xml = open(expected_xml_filename).read().replace(">", ">\n")
+        with open(expected_xml_filename) as f:
+            actual_xml = f.read().replace(">", ">\n")
         assert actual_xml.splitlines() == expected_xml.splitlines()
 
     def test_run(self):

tests/test_modules/test_ADCore/test_statspluginpart.py

@@ -43,6 +43,7 @@ def test_configure(self):
 <Attributes>
 <Attribute addr="0" datatype="DOUBLE" description="Sum of the array" name="STATS_TOTAL" source="TOTAL" type="PARAM" />
 </Attributes>"""
-        actual_xml = open(expected_filename).read().replace(">", ">\n")
+        with open(expected_filename) as f:
+            actual_xml = f.read().replace(">", ">\n")
         assert actual_xml.splitlines() == expected_xml.splitlines()
 

tests/test_modules/test_builtin/test_managercontroller.py

@@ -91,8 +91,8 @@ def check_expected_save(self, x=0.0, y=0.0, visible="true", attr="defaultv"):
             "attr": "%s"
           }
         }""" % (x, y, visible, attr)).splitlines()]
-        actual = [x.strip() for x in open(
-            "/tmp/mainBlock/testSaveLayout.json").readlines()]
+        with open("/tmp/mainBlock/testSaveLayout.json") as f:
+            actual = [x.strip() for x in f.readlines()]
         assert actual == expected
 
     def test_save(self):