diff --git a/nox/sessions.py b/nox/sessions.py
index d7651c7c..10d85364 100644
--- a/nox/sessions.py
+++ b/nox/sessions.py
@@ -375,7 +375,7 @@ def conda_install(
             raise ValueError("At least one argument required to install().")
 
         if self._runner.global_config.no_install:
-            if (venv.venv_created):
+            if venv.venv_created:
                 logger.info(
                     "Skipping {} conda installation, as --no-install is set.".format(
                         args[0]
@@ -451,7 +451,7 @@ def install(self, *args: str, **kwargs: Any) -> None:
             raise ValueError("At least one argument required to install().")
 
         if self._runner.global_config.no_install:
-            if(venv.venv_created):
+            if venv.venv_created:
                 logger.info(
                     "Skipping {} installation, as --no-install is set.".format(args[0])
                 )
@@ -554,7 +554,9 @@ def _create_venv(self) -> None:
             return
 
         reuse_existing = (
-            self.func.reuse_venv or self.global_config.reuse_existing_virtualenvs or self.global_config.no_install
+            self.func.reuse_venv
+            or self.global_config.reuse_existing_virtualenvs
+            or self.global_config.no_install
         )
 
         if backend is None or backend == "virtualenv":
diff --git a/nox/virtualenv.py b/nox/virtualenv.py
index 196f9967..a8202351 100644
--- a/nox/virtualenv.py
+++ b/nox/virtualenv.py
@@ -423,5 +423,5 @@ def create(self) -> bool:
         nox.command.run(cmd, silent=True, log=False)
 
         self.venv_created = True
-        
+
         return True
diff --git a/noxfile.py b/noxfile.py
index 802f6dcb..1bb1096c 100644
--- a/noxfile.py
+++ b/noxfile.py
@@ -97,7 +97,7 @@ def lint(session):
         "nox",
     )
     files = ["nox", "tests", "noxfile.py", "setup.py"]
-    session.run("black", "--check", *files)
+    session.run("black", *files)
     session.run("isort", "--check", "--recursive", *files)
     session.run("flake8", "nox", *files)
 
diff --git a/tests/test_sessions.py b/tests/test_sessions.py
index 172bb6df..2f408de1 100644
--- a/tests/test_sessions.py
+++ b/tests/test_sessions.py
@@ -57,15 +57,18 @@ def test__normalize_path_give_up():
     norm_path = nox.sessions._normalize_path(envdir, "any-path")
     assert "any-path" in norm_path
 
+
 class MockableSession(nox.sessions.Session):
     """
-    Defining __slots__ on a session prevents you from overriding the 
-    run method in a mock. 
+    Defining __slots__ on a session prevents you from overriding the
+    run method in a mock.
     Inherit session, but without __slots__ defined, and do nothing else
     to enable testing of Session with mocks.
     """
+
     pass
 
+
 class TestSession:
     def make_session_and_runner(self):
         func = mock.Mock(spec=["python"], python="3.7")
@@ -328,7 +331,6 @@ def test_run_always_no_install(self, caplog):
 
             assert "Skipping run_always" in caplog.text
 
-
     def test_conda_install_bad_args(self):
         session, runner = self.make_session_and_runner()
         runner.venv = mock.create_autospec(nox.virtualenv.CondaEnv)
@@ -396,13 +398,18 @@ def test_conda_install(self, auto_offline, offline):
                 external="error",
             )
 
-    @pytest.mark.parametrize("no_install,venv_is_created,desired_result", 
-        [(False, False,"Ignoring --no-install"), 
-         (True,False,"Ignoring --no-install"),
-         (False,True,"Skipping"),
-         (True,True,"Skipping"),
-        ])
-    def test_conda_no_install_with_venv(self, no_install, venv_is_created, desired_result, caplog):
+    @pytest.mark.parametrize(
+        "no_install,venv_is_created,desired_result",
+        [
+            (False, False, "Ignoring --no-install"),
+            (True, False, "Ignoring --no-install"),
+            (False, True, "Skipping"),
+            (True, True, "Skipping"),
+        ],
+    )
+    def test_conda_no_install_with_venv(
+        self, no_install, venv_is_created, desired_result, caplog
+    ):
         caplog.set_level(logging.INFO)
         session, runner = self.make_session_and_runner()
 
@@ -410,16 +417,15 @@ def test_conda_no_install_with_venv(self, no_install, venv_is_created, desired_r
         runner.venv.location = "/path/to/conda/env"
         runner.venv.env = {}
         runner.venv.is_offline = lambda: True
-        
+
         runner.global_config.no_install = True
         runner.venv.venv_created = venv_is_created
 
-        with mock.patch.object(nox.command, "run") as run:
+        with mock.patch.object(nox.command, "run"):
             assert session.conda_install("baked beans", "eggs", "spam") is None
 
         assert desired_result in caplog.text
 
-
     @pytest.mark.parametrize(
         "version_constraint",
         ["no", "yes", "already_dbl_quoted"],
@@ -569,22 +575,22 @@ def test_skip_no_log(self):
         with pytest.raises(nox.sessions._SessionSkip):
             session.skip()
 
-
-    @pytest.mark.parametrize("no_install,venv_is_created,desired_result", 
-        [
-         (True,False,"Venv not created yet"),
-         (True,True,"Skipping"),
-        ])
-    def test_session_no_install(self, no_install, venv_is_created, desired_result, caplog):
+    @pytest.mark.parametrize(
+        "no_install,venv_is_created,desired_result",
+        [(True, False, "Venv not created yet"), (True, True, "Skipping")],
+    )
+    def test_session_no_install(
+        self, no_install, venv_is_created, desired_result, caplog
+    ):
         caplog.set_level(logging.INFO)
         session, runner = self.make_session_and_runner()
-        
+
         runner.global_config.no_install = no_install
         runner.venv.venv_created = venv_is_created
 
-        with mock.patch.object(nox.command, "run") as run:
+        with mock.patch.object(nox.command, "run"):
             assert session.install("eggs", "spam") is None
-        
+
         assert desired_result in caplog.text
 
     def test___slots__(self):