Use context manager instead of plain open (#1211)

Context manager with open closes the files after usage.

When the object is already a pathlib.Path i used read_text
write_text functions

In some cases pathlib.Path.open were used in context manager,
it is basically the same as builtin open.

Thanks, Konstantin Baikov!

datasette/app.py

@@ -212,7 +212,7 @@ class Datasette:
             and (config_dir / "inspect-data.json").exists()
             and not inspect_data
         ):
-            inspect_data = json.load((config_dir / "inspect-data.json").open())
+            inspect_data = json.loads((config_dir / "inspect-data.json").read_text())
             if immutables is None:
                 immutable_filenames = [i["file"] for i in inspect_data.values()]
                 immutables = [
@@ -269,7 +269,7 @@ class Datasette:
         if config_dir and (config_dir / "config.json").exists():
             raise StartupError("config.json should be renamed to settings.json")
         if config_dir and (config_dir / "settings.json").exists() and not config:
-            config = json.load((config_dir / "settings.json").open())
+            config = json.loads((config_dir / "settings.json").read_text())
         self._settings = dict(DEFAULT_SETTINGS, **(config or {}))
         self.renderers = {}  # File extension -> (renderer, can_render) functions
         self.version_note = version_note
@@ -450,11 +450,10 @@ class Datasette:
 
     def app_css_hash(self):
         if not hasattr(self, "_app_css_hash"):
-            self._app_css_hash = hashlib.sha1(
+            with open(os.path.join(str(app_root), "datasette/static/app.css")) as fp:
-                open(os.path.join(str(app_root), "datasette/static/app.css"))
+                self._app_css_hash = hashlib.sha1(fp.read().encode("utf8")).hexdigest()[
-                .read()
+                    :6
-                .encode("utf8")
+                ]
-            ).hexdigest()[:6]
         return self._app_css_hash
 
     async def get_canned_queries(self, database_name, actor):

datasette/cli.py

@@ -125,13 +125,13 @@ def cli():
 @sqlite_extensions
 def inspect(files, inspect_file, sqlite_extensions):
     app = Datasette([], immutables=files, sqlite_extensions=sqlite_extensions)
-    if inspect_file == "-":
-        out = sys.stdout
-    else:
-        out = open(inspect_file, "w")
     loop = asyncio.get_event_loop()
     inspect_data = loop.run_until_complete(inspect_(files, sqlite_extensions))
-    out.write(json.dumps(inspect_data, indent=2))
+    if inspect_file == "-":
+        sys.stdout.write(json.dumps(inspect_data, indent=2))
+    else:
+        with open(inspect_file, "w") as fp:
+            fp.write(json.dumps(inspect_data, indent=2))
 
 
 async def inspect_(files, sqlite_extensions):
@@ -475,7 +475,8 @@ def serve(
 
     inspect_data = None
     if inspect_file:
-        inspect_data = json.load(open(inspect_file))
+        with open(inspect_file) as fp:
+            inspect_data = json.load(fp)
 
     metadata_data = None
     if metadata:

datasette/publish/cloudrun.py

@@ -141,9 +141,11 @@ def publish_subcommand(publish):
             if show_files:
                 if os.path.exists("metadata.json"):
                     print("=== metadata.json ===\n")
-                    print(open("metadata.json").read())
+                    with open("metadata.json") as fp:
+                        print(fp.read())
                 print("\n==== Dockerfile ====\n")
-                print(open("Dockerfile").read())
+                with open("Dockerfile") as fp:
+                    print(fp.read())
                 print("\n====================\n")
 
             image_id = f"gcr.io/{project}/{name}"

datasette/publish/heroku.py

@@ -171,9 +171,11 @@ def temporary_heroku_directory(
         os.chdir(tmp.name)
 
         if metadata_content:
-            open("metadata.json", "w").write(json.dumps(metadata_content, indent=2))
+            with open("metadata.json", "w") as fp:
+                fp.write(json.dumps(metadata_content, indent=2))
 
-        open("runtime.txt", "w").write("python-3.8.7")
+        with open("runtime.txt", "w") as fp:
+            fp.write("python-3.8.7")
 
         if branch:
             install = [
@@ -182,11 +184,11 @@ def temporary_heroku_directory(
         else:
             install = ["datasette"] + list(install)
 
-        open("requirements.txt", "w").write("\n".join(install))
+        with open("requirements.txt", "w") as fp:
+            fp.write("\n".join(install))
         os.mkdir("bin")
-        open("bin/post_compile", "w").write(
+        with open("bin/post_compile", "w") as fp:
-            "datasette inspect --inspect-file inspect-data.json"
+            fp.write("datasette inspect --inspect-file inspect-data.json")
-        )
 
         extras = []
         if template_dir:
@@ -218,7 +220,8 @@ def temporary_heroku_directory(
         procfile_cmd = "web: datasette serve --host 0.0.0.0 {quoted_files} --cors --port $PORT --inspect-file inspect-data.json {extras}".format(
             quoted_files=quoted_files, extras=" ".join(extras)
         )
-        open("Procfile", "w").write(procfile_cmd)
+        with open("Procfile", "w") as fp:
+            fp.write(procfile_cmd)
 
         for path, filename in zip(file_paths, file_names):
             link_or_copy(path, os.path.join(tmp.name, filename))

datasette/utils/__init__.py

@@ -428,8 +428,10 @@ def temporary_docker_directory(
         )
         os.chdir(datasette_dir)
         if metadata_content:
-            open("metadata.json", "w").write(json.dumps(metadata_content, indent=2))
+            with open("metadata.json", "w") as fp:
-        open("Dockerfile", "w").write(dockerfile)
+                fp.write(json.dumps(metadata_content, indent=2))
+        with open("Dockerfile", "w") as fp:
+            fp.write(dockerfile)
         for path, filename in zip(file_paths, file_names):
             link_or_copy(path, os.path.join(datasette_dir, filename))
         if template_dir:

setup.py

@@ -17,7 +17,8 @@ def get_version():
         os.path.dirname(os.path.abspath(__file__)), "datasette", "version.py"
     )
     g = {}
-    exec(open(path).read(), g)
+    with open(path) as fp:
+        exec(fp.read(), g)
     return g["__version__"]
 
 

tests/conftest.py

@@ -75,10 +75,8 @@ def check_permission_actions_are_documented():
     from datasette.plugins import pm
 
     content = (
-        (pathlib.Path(__file__).parent.parent / "docs" / "authentication.rst")
+        pathlib.Path(__file__).parent.parent / "docs" / "authentication.rst"
-        .open()
+    ).read_text()
-        .read()
-    )
     permissions_re = re.compile(r"\.\. _permissions_([^\s:]+):")
     documented_permission_actions = set(permissions_re.findall(content)).union(
         UNDOCUMENTED_PERMISSIONS

tests/fixtures.py

@@ -789,7 +789,8 @@ def cli(db_filename, metadata, plugins_path, recreate, extra_db_filename):
             conn.executescript(GENERATED_COLUMNS_SQL)
     print(f"Test tables written to {db_filename}")
     if metadata:
-        open(metadata, "w").write(json.dumps(METADATA, indent=4))
+        with open(metadata, "w") as fp:
+            fp.write(json.dumps(METADATA, indent=4))
         print(f"- metadata written to {metadata}")
     if plugins_path:
         path = pathlib.Path(plugins_path)
@@ -798,7 +799,7 @@ def cli(db_filename, metadata, plugins_path, recreate, extra_db_filename):
         test_plugins = pathlib.Path(__file__).parent / "plugins"
         for filepath in test_plugins.glob("*.py"):
             newpath = path / filepath.name
-            newpath.write_text(filepath.open().read())
+            newpath.write_text(filepath.read_text())
             print(f"  Wrote plugin: {newpath}")
     if extra_db_filename:
         if pathlib.Path(extra_db_filename).exists():

tests/test_cli.py

@@ -49,7 +49,8 @@ def test_inspect_cli_writes_to_file(app_client):
         cli, ["inspect", "fixtures.db", "--inspect-file", "foo.json"]
     )
     assert 0 == result.exit_code, result.output
-    data = json.load(open("foo.json"))
+    with open("foo.json") as fp:
+        data = json.load(fp)
     assert ["fixtures"] == list(data.keys())
 
 

tests/test_cli_serve_get.py

@@ -14,7 +14,8 @@ def test_serve_with_get(tmp_path_factory):
 
         @hookimpl
         def startup(datasette):
-            open("{}", "w").write("hello")
+            with open("{}", "w") as fp:
+                fp.write("hello")
     """.format(
                 str(plugins_dir / "hello.txt")
             ),

tests/test_docs.py

@@ -19,13 +19,13 @@ def get_headings(content, underline="-"):
 
 
 def get_labels(filename):
-    content = (docs_path / filename).open().read()
+    content = (docs_path / filename).read_text()
     return set(label_re.findall(content))
 
 
 @pytest.fixture(scope="session")
 def settings_headings():
-    return get_headings((docs_path / "settings.rst").open().read(), "~")
+    return get_headings((docs_path / "settings.rst").read_text(), "~")
 
 
 @pytest.mark.parametrize("setting", app.SETTINGS)
@@ -43,7 +43,7 @@ def test_settings_are_documented(settings_headings, setting):
     ),
 )
 def test_help_includes(name, filename):
-    expected = open(str(docs_path / filename)).read()
+    expected = (docs_path / filename).read_text()
     runner = CliRunner()
     result = runner.invoke(cli, name.split() + ["--help"], terminal_width=88)
     actual = f"$ datasette {name} --help\n\n{result.output}"
@@ -55,7 +55,7 @@ def test_help_includes(name, filename):
 
 @pytest.fixture(scope="session")
 def plugin_hooks_content():
-    return (docs_path / "plugin_hooks.rst").open().read()
+    return (docs_path / "plugin_hooks.rst").read_text()
 
 
 @pytest.mark.parametrize(

tests/test_package.py

@@ -32,7 +32,8 @@ def test_package(mock_call, mock_which):
     capture = CaptureDockerfile()
     mock_call.side_effect = capture
     with runner.isolated_filesystem():
-        open("test.db", "w").write("data")
+        with open("test.db", "w") as fp:
+            fp.write("data")
         result = runner.invoke(cli.cli, ["package", "test.db", "--secret", "sekrit"])
         assert 0 == result.exit_code
         mock_call.assert_has_calls([mock.call(["docker", "build", "."])])
@@ -47,7 +48,8 @@ def test_package_with_port(mock_call, mock_which):
     mock_call.side_effect = capture
     runner = CliRunner()
     with runner.isolated_filesystem():
-        open("test.db", "w").write("data")
+        with open("test.db", "w") as fp:
+            fp.write("data")
         result = runner.invoke(
             cli.cli, ["package", "test.db", "-p", "8080", "--secret", "sekrit"]
         )

tests/test_plugins.py

@@ -225,7 +225,8 @@ def test_plugin_config_env_from_list(app_client):
 
 
 def test_plugin_config_file(app_client):
-    open(TEMP_PLUGIN_SECRET_FILE, "w").write("FROM_FILE")
+    with open(TEMP_PLUGIN_SECRET_FILE, "w") as fp:
+        fp.write("FROM_FILE")
     assert {"foo": "FROM_FILE"} == app_client.ds.plugin_config("file-plugin")
     # Ensure secrets aren't visible in /-/metadata.json
     metadata = app_client.get("/-/metadata.json")

tests/test_publish_cloudrun.py

@@ -11,7 +11,8 @@ def test_publish_cloudrun_requires_gcloud(mock_which):
     mock_which.return_value = False
     runner = CliRunner()
     with runner.isolated_filesystem():
-        open("test.db", "w").write("data")
+        with open("test.db", "w") as fp:
+            fp.write("data")
         result = runner.invoke(cli.cli, ["publish", "cloudrun", "test.db"])
         assert result.exit_code == 1
         assert "Publishing to Google Cloud requires gcloud" in result.output
@@ -40,7 +41,8 @@ def test_publish_cloudrun_prompts_for_service(
     mock_which.return_value = True
     runner = CliRunner()
     with runner.isolated_filesystem():
-        open("test.db", "w").write("data")
+        with open("test.db", "w") as fp:
+            fp.write("data")
         result = runner.invoke(
             cli.cli, ["publish", "cloudrun", "test.db"], input="input-service"
         )
@@ -81,7 +83,8 @@ def test_publish_cloudrun(mock_call, mock_output, mock_which):
     mock_which.return_value = True
     runner = CliRunner()
     with runner.isolated_filesystem():
-        open("test.db", "w").write("data")
+        with open("test.db", "w") as fp:
+            fp.write("data")
         result = runner.invoke(
             cli.cli, ["publish", "cloudrun", "test.db", "--service", "test"]
         )
@@ -120,7 +123,8 @@ def test_publish_cloudrun_memory(
     mock_which.return_value = True
     runner = CliRunner()
     with runner.isolated_filesystem():
-        open("test.db", "w").write("data")
+        with open("test.db", "w") as fp:
+            fp.write("data")
         result = runner.invoke(
             cli.cli,
             ["publish", "cloudrun", "test.db", "--service", "test", "--memory", memory],
@@ -152,17 +156,19 @@ def test_publish_cloudrun_plugin_secrets(mock_call, mock_output, mock_which):
 
     runner = CliRunner()
     with runner.isolated_filesystem():
-        open("test.db", "w").write("data")
+        with open("test.db", "w") as fp:
-        open("metadata.yml", "w").write(
+            fp.write("data")
-            textwrap.dedent(
+        with open("metadata.yml", "w") as fp:
-                """
+            fp.write(
+                textwrap.dedent(
+                    """
                 title: Hello from metadata YAML
                 plugins:
                   datasette-auth-github:
                     foo: bar
                 """
-            ).strip()
+                ).strip()
-        )
+            )
         result = runner.invoke(
             cli.cli,
             [
@@ -228,7 +234,8 @@ def test_publish_cloudrun_apt_get_install(mock_call, mock_output, mock_which):
 
     runner = CliRunner()
     with runner.isolated_filesystem():
-        open("test.db", "w").write("data")
+        with open("test.db", "w") as fp:
+            fp.write("data")
         result = runner.invoke(
             cli.cli,
             [
@@ -295,7 +302,8 @@ def test_publish_cloudrun_extra_options(
 
     runner = CliRunner()
     with runner.isolated_filesystem():
-        open("test.db", "w").write("data")
+        with open("test.db", "w") as fp:
+            fp.write("data")
         result = runner.invoke(
             cli.cli,
             [

tests/test_publish_heroku.py

@@ -8,7 +8,8 @@ def test_publish_heroku_requires_heroku(mock_which):
     mock_which.return_value = False
     runner = CliRunner()
     with runner.isolated_filesystem():
-        open("test.db", "w").write("data")
+        with open("test.db", "w") as fp:
+            fp.write("data")
         result = runner.invoke(cli.cli, ["publish", "heroku", "test.db"])
         assert result.exit_code == 1
         assert "Publishing to Heroku requires heroku" in result.output
@@ -22,7 +23,8 @@ def test_publish_heroku_installs_plugin(mock_call, mock_check_output, mock_which
     mock_check_output.side_effect = lambda s: {"['heroku', 'plugins']": b""}[repr(s)]
     runner = CliRunner()
     with runner.isolated_filesystem():
-        open("t.db", "w").write("data")
+        with open("t.db", "w") as fp:
+            fp.write("data")
         result = runner.invoke(cli.cli, ["publish", "heroku", "t.db"], input="y\n")
         assert 0 != result.exit_code
     mock_check_output.assert_has_calls(
@@ -54,7 +56,8 @@ def test_publish_heroku(mock_call, mock_check_output, mock_which):
     }[repr(s)]
     runner = CliRunner()
     with runner.isolated_filesystem():
-        open("test.db", "w").write("data")
+        with open("test.db", "w") as fp:
+            fp.write("data")
         result = runner.invoke(
             cli.cli, ["publish", "heroku", "test.db", "--tar", "gtar"]
         )
@@ -88,7 +91,8 @@ def test_publish_heroku_plugin_secrets(mock_call, mock_check_output, mock_which)
     }[repr(s)]
     runner = CliRunner()
     with runner.isolated_filesystem():
-        open("test.db", "w").write("data")
+        with open("test.db", "w") as fp:
+            fp.write("data")
         result = runner.invoke(
             cli.cli,
             [

tests/test_utils.py

@@ -232,7 +232,8 @@ def test_to_css_class(s, expected):
 def test_temporary_docker_directory_uses_hard_link():
     with tempfile.TemporaryDirectory() as td:
         os.chdir(td)
-        open("hello", "w").write("world")
+        with open("hello", "w") as fp:
+            fp.write("world")
         # Default usage of this should use symlink
         with utils.temporary_docker_directory(
             files=["hello"],
@@ -249,7 +250,8 @@ def test_temporary_docker_directory_uses_hard_link():
             secret="secret",
         ) as temp_docker:
             hello = os.path.join(temp_docker, "hello")
-            assert "world" == open(hello).read()
+            with open(hello) as fp:
+                assert "world" == fp.read()
             # It should be a hard link
             assert 2 == os.stat(hello).st_nlink
 
@@ -260,7 +262,8 @@ def test_temporary_docker_directory_uses_copy_if_hard_link_fails(mock_link):
     mock_link.side_effect = OSError
     with tempfile.TemporaryDirectory() as td:
         os.chdir(td)
-        open("hello", "w").write("world")
+        with open("hello", "w") as fp:
+            fp.write("world")
         # Default usage of this should use symlink
         with utils.temporary_docker_directory(
             files=["hello"],
@@ -277,7 +280,8 @@ def test_temporary_docker_directory_uses_copy_if_hard_link_fails(mock_link):
             secret=None,
         ) as temp_docker:
             hello = os.path.join(temp_docker, "hello")
-            assert "world" == open(hello).read()
+            with open(hello) as fp:
+                assert "world" == fp.read()
             # It should be a copy, not a hard link
             assert 1 == os.stat(hello).st_nlink
 
@@ -285,7 +289,8 @@ def test_temporary_docker_directory_uses_copy_if_hard_link_fails(mock_link):
 def test_temporary_docker_directory_quotes_args():
     with tempfile.TemporaryDirectory() as td:
         os.chdir(td)
-        open("hello", "w").write("world")
+        with open("hello", "w") as fp:
+            fp.write("world")
         with utils.temporary_docker_directory(
             files=["hello"],
             name="t",
@@ -301,7 +306,8 @@ def test_temporary_docker_directory_quotes_args():
             secret="secret",
         ) as temp_docker:
             df = os.path.join(temp_docker, "Dockerfile")
-            df_contents = open(df).read()
+            with open(df) as fp:
+                df_contents = fp.read()
             assert "'$PWD'" in df_contents
             assert "'--$HOME'" in df_contents
             assert "ENV DATASETTE_SECRET 'secret'" in df_contents

update-docs-help.py

@@ -18,7 +18,7 @@ def update_help_includes():
         result = runner.invoke(cli, name.split() + ["--help"], terminal_width=88)
         actual = f"$ datasette {name} --help\n\n{result.output}"
         actual = actual.replace("Usage: cli ", "Usage: datasette ")
-        open(docs_path / filename, "w").write(actual)
+        (docs_path / filename).write_text(actual)
 
 
 if __name__ == "__main__":