Avoid importing buildenv and metadata modules during autocompletion

news/4768.feature.rst

@@ -0,0 +1 @@
+Speedup tab autocompletion by lazy-importing certain modules.

src/pip/_internal/build_env.py

@@ -4,7 +4,6 @@
 
 import logging
 import os
-import pathlib
 import site
 import sys
 import textwrap
@@ -18,7 +17,6 @@
 
 from pip._vendor.packaging.version import Version
 
-from pip import __file__ as pip_location
 from pip._internal.cli.spinners import open_rich_spinner, open_spinner
 from pip._internal.exceptions import (
     BuildDependencyInstallError,
@@ -30,6 +28,7 @@
 from pip._internal.metadata import get_default_environment, get_environment
 from pip._internal.utils.deprecation import deprecated
 from pip._internal.utils.logging import VERBOSE, capture_logging
+from pip._internal.utils.misc import get_runnable_pip
 from pip._internal.utils.packaging import get_requirement
 from pip._internal.utils.subprocess import call_subprocess
 from pip._internal.utils.temp_dir import TempDirectory, tempdir_kinds
@@ -61,22 +60,6 @@ def __init__(self, path: str) -> None:
         self.lib_dirs = _dedup(scheme.purelib, scheme.platlib)
 
 
-def get_runnable_pip() -> str:
-    """Get a file to pass to a Python executable, to run the currently-running pip.
-
-    This is used to run a pip subprocess, for installing requirements into the build
-    environment.
-    """
-    source = pathlib.Path(pip_location).resolve().parent
-
-    if not source.is_dir():
-        # This would happen if someone is using pip from inside a zip file. In that
-        # case, we can use that directly.
-        return str(source)
-
-    return os.fsdecode(source / "__pip-runner__.py")
-
-
 def _get_system_sitepackages() -> set[str]:
     """Get system site packages
 

src/pip/_internal/cli/autocompletion.py

@@ -11,7 +11,6 @@
 
 from pip._internal.cli.main_parser import create_main_parser
 from pip._internal.commands import commands_dict, create_command
-from pip._internal.metadata import get_default_environment
 
 
 def autocomplete() -> None:
@@ -51,6 +50,8 @@ def autocomplete() -> None:
             "uninstall",
         ]
         if should_list_installed:
+            from pip._internal.metadata import get_default_environment
+
             env = get_default_environment()
             lc = current.lower()
             installed = [

src/pip/_internal/cli/main_parser.py

@@ -6,12 +6,11 @@
 import subprocess
 import sys
 
-from pip._internal.build_env import get_runnable_pip
 from pip._internal.cli import cmdoptions
 from pip._internal.cli.parser import ConfigOptionParser, UpdatingDefaultsHelpFormatter
 from pip._internal.commands import commands_dict, get_similar_commands
 from pip._internal.exceptions import CommandError
-from pip._internal.utils.misc import get_pip_version, get_prog
+from pip._internal.utils.misc import get_pip_version, get_prog, get_runnable_pip
 
 __all__ = ["create_main_parser", "parse_command"]
 

src/pip/_internal/utils/misc.py

@@ -5,6 +5,7 @@
 import hashlib
 import logging
 import os
+import pathlib
 import posixpath
 import shutil
 import stat
@@ -31,6 +32,7 @@
 from pip._vendor.packaging.requirements import Requirement
 from pip._vendor.pyproject_hooks import BuildBackendHookCaller
 
+from pip import __file__ as pip_location
 from pip import __version__
 from pip._internal.exceptions import CommandError, ExternallyManagedEnvironment
 from pip._internal.locations import get_major_minor_version
@@ -74,6 +76,22 @@ def get_pip_version() -> str:
     return f"pip {__version__} from {pip_pkg_dir} (python {get_major_minor_version()})"
 
 
+def get_runnable_pip() -> str:
+    """Get a file to pass to a Python executable, to run the currently-running pip.
+
+    This is used to run a pip subprocess, for installing requirements into the build
+    environment.
+    """
+    source = pathlib.Path(pip_location).resolve().parent
+
+    if not source.is_dir():
+        # This would happen if someone is using pip from inside a zip file. In that
+        # case, we can use that directly.
+        return str(source)
+
+    return os.fsdecode(source / "__pip-runner__.py")
+
+
 def normalize_version_info(py_version_info: tuple[int, ...]) -> tuple[int, int, int]:
     """
     Convert a tuple of ints representing a Python version to one of length