Warn Python 3.5 support is deprecated and will be removed in pip 21.0…

…, Jan 2021

news/8181.removal

@@ -0,0 +1 @@
+Deprecate support for Python 3.5

src/pip/_internal/cli/base_command.py

@@ -158,7 +158,19 @@ def _main(self, args):
                     "1st, 2020. Please upgrade your Python as Python 2.7 "
                     "is no longer maintained. "
                 ) + message
-            deprecated(message, replacement=None, gone_in=None)
+            deprecated(message, replacement=None, gone_in="21.0")
+
+        if (
+            sys.version_info[:2] == (3, 5) and
+            not options.no_python_version_warning
+        ):
+            message = (
+                "Python 3.5 reached the end of its life on September "
+                "13th, 2020. Please upgrade your Python as Python 3.5 "
+                "is no longer maintained. pip 21.0 will drop support "
+                "for Python 3.5 in January 2021."
+            )
+            deprecated(message, replacement=None, gone_in="21.0")
 
         # TODO: Try to get these passing down from the command?
         #       without resorting to os.environ to hold these.

tests/conftest.py

@@ -470,8 +470,8 @@ def in_memory_pip():
 
 @pytest.fixture(scope="session")
 def deprecated_python():
-    """Used to indicate whether pip deprecated this python version"""
-    return sys.version_info[:2] in [(2, 7)]
+    """Used to indicate whether pip deprecated this Python version"""
+    return sys.version_info[:2] in [(2, 7), (3, 5)]
 
 
 @pytest.fixture(scope="session")