pip list --not-required --outdated should list only outdated packages that are not dependencies of installed packages

news/5737.bugfix

@@ -0,0 +1 @@
+`pip list --outdated --not-required` should list only outdated packages that are not dependencies of installed packages

src/pip/_internal/commands/list.py

@@ -134,14 +134,14 @@ class ListCommand(Command):
             include_editables=options.include_editable,
         )
 
+        if options.not_required:
+            packages = self.get_not_required(packages, options)
+
         if options.outdated:
             packages = self.get_outdated(packages, options)
         elif options.uptodate:
             packages = self.get_uptodate(packages, options)
 
-        if options.not_required:
-            packages = self.get_not_required(packages, options)
-
         self.output_package_listing(packages, options)
 
     def get_outdated(self, packages, options):

tests/functional/test_list.py

@@ -384,6 +384,22 @@ def test_outdated_editables_columns_flag(script, data):
     )
 
 
+@pytest.mark.network
+def test_outdated_not_required_flag(script, data):
+    """
+    test the behavior of --outdated --not-required flag in the list command
+    """
+    script.pip(
+        'install', '-f', data.find_links, '--no-index',
+        'simple==2.0', 'require_simple==1.0'
+    )
+    result = script.pip(
+        'list', '-f', data.find_links, '--no-index', '--outdated',
+        '--not-required', '--format=json',
+    )
+    assert [] == json.loads(result.stdout)
+
+
 def test_outdated_pre(script, data):
     script.pip('install', '-f', data.find_links, '--no-index', 'simple==1.0')