Split bin_user and bin_prefix implementations

Module-level logic is bad.

src/pip/_internal/locations/__init__.py

@@ -8,6 +8,7 @@
 from . import _distutils, _sysconfig
 from .base import (
     USER_CACHE_DIR,
+    get_bin_user,
     get_major_minor_version,
     get_src_prefix,
     site_packages,
@@ -100,14 +101,6 @@ def get_bin_prefix():
     return old
 
 
-def get_bin_user():
-    # type: () -> str
-    old = _distutils.get_bin_user()
-    new = _sysconfig.get_bin_user()
-    _warn_if_mismatch(pathlib.Path(old), pathlib.Path(new), key="bin_user")
-    return old
-
-
 def get_purelib():
     # type: () -> str
     """Return the default pure-Python lib location."""

src/pip/_internal/locations/_distutils.py

@@ -4,17 +4,18 @@
 # mypy: strict-optional=False
 
 import os
-import os.path
+import sys
 from distutils.cmd import Command as DistutilsCommand
 from distutils.command.install import SCHEME_KEYS
 from distutils.command.install import install as distutils_install_command
 from distutils.sysconfig import get_python_lib
 from typing import Dict, List, Optional, Tuple, Union, cast
 
 from pip._internal.models.scheme import Scheme
+from pip._internal.utils.compat import WINDOWS
 from pip._internal.utils.virtualenv import running_under_virtualenv
 
-from .base import bin_py, bin_user, get_major_minor_version
+from .base import get_major_minor_version
 
 
 def _distutils_scheme(
@@ -118,12 +119,17 @@ def get_scheme(
 
 def get_bin_prefix():
     # type: () -> str
-    return bin_py
-
-
-def get_bin_user():
-    # type: () -> str
-    return bin_user
+    if WINDOWS:
+        bin_py = os.path.join(sys.prefix, "Scripts")
+        # buildout uses 'bin' on Windows too?
+        if not os.path.exists(bin_py):
+            bin_py = os.path.join(sys.prefix, "bin")
+        return bin_py
+    # Forcing to use /usr/local/bin for standard macOS framework installs
+    # Also log to ~/Library/Logs/ for use with the Console.app log viewer
+    if sys.platform[:6] == "darwin" and sys.prefix[:16] == "/System/Library/":
+        return "/usr/local/bin"
+    return os.path.join(sys.prefix, "bin")
 
 
 def get_purelib():

src/pip/_internal/locations/_sysconfig.py

@@ -9,7 +9,7 @@
 from pip._internal.models.scheme import SCHEME_KEYS, Scheme
 from pip._internal.utils.virtualenv import running_under_virtualenv
 
-from .base import bin_user, get_major_minor_version
+from .base import get_major_minor_version
 
 logger = logging.getLogger(__name__)
 
@@ -139,14 +139,6 @@ def get_bin_prefix():
     return sysconfig.get_paths(scheme=_infer_scheme("prefix"))["scripts"]
 
 
-def get_bin_user():
-    # type: () -> str
-    # pip puts the scripts directory in site-packages, not under userbase.
-    # I'm honestly not sure if this is a bug (because ``get_scheme()`` puts it
-    # correctly under userbase), but we need to be compatible.
-    return bin_user
-
-
 def get_purelib():
     # type: () -> str
     return sysconfig.get_paths()["purelib"]

src/pip/_internal/locations/base.py

@@ -49,18 +49,18 @@ def get_src_prefix():
     user_site = site.USER_SITE
 
 
-if WINDOWS:
-    bin_py = os.path.join(sys.prefix, "Scripts")
-    bin_user = os.path.join(user_site, "Scripts")
-    # buildout uses 'bin' on Windows too?
-    if not os.path.exists(bin_py):
-        bin_py = os.path.join(sys.prefix, "bin")
-        bin_user = os.path.join(user_site, "bin")
-else:
-    bin_py = os.path.join(sys.prefix, "bin")
-    bin_user = os.path.join(user_site, "bin")
+def get_bin_user():
+    # type: () -> str
+    """Get the user-site scripts directory.
 
-    # Forcing to use /usr/local/bin for standard macOS framework installs
-    # Also log to ~/Library/Logs/ for use with the Console.app log viewer
-    if sys.platform[:6] == "darwin" and sys.prefix[:16] == "/System/Library/":
-        bin_py = "/usr/local/bin"
+    Pip puts the scripts directory in site-packages, not under userbase.
+    I'm honestly not sure if this is a bug (because ``get_scheme()`` puts it
+    correctly under userbase), but we need to keep backwards compatibility.
+    """
+    assert user_site is not None, "user site unavailable"
+    if not WINDOWS:
+        return os.path.join(user_site, "bin")
+    # Special case for buildout, which uses 'bin' on Windows too?
+    if not os.path.exists(os.path.join(sys.prefix, "Scripts")):
+        os.path.join(user_site, "bin")
+    return os.path.join(user_site, "Scripts")