← Back
Editing: _sysconfig.py
from __future__ import annotations import logging import os import sys import sysconfig from typing import Callable from pip._internal.exceptions import InvalidSchemeCombination, UserInstallationInvalid from pip._internal.models.scheme import SCHEME_KEYS, Scheme from pip._internal.utils.virtualenv import running_under_virtualenv from .base import change_root, get_major_minor_version, is_osx_framework logger = logging.getLogger(__name__) # Notes on _infer_* functions. # Unfortunately ``get_default_scheme()`` didn't exist before 3.10, so there's no # way to ask things like "what is the '_prefix' scheme on this platform". These # functions try to answer that with some heuristics while accounting for ad-hoc # platforms not covered by CPython's default sysconfig implementation. If the # ad-hoc implementation does not fully implement sysconfig, we'll fall back to # a POSIX scheme. _AVAILABLE_SCHEMES = set(sysconfig.get_scheme_names()) _PREFERRED_SCHEME_API: Callable[[str], str] | None = getattr( sysconfig, "get_preferred_scheme", None ) def _should_use_osx_framework_prefix() -> bool: """Check for Apple's ``osx_framework_library`` scheme. Python distributed by Apple's Command Line Tools has this special scheme that's used when: * This is a framework build. * We are installing into the system prefix. This does not account for ``pip install --prefix`` (also means we're not installing to the system prefix), which should use ``posix_prefix``, but logic here means ``_infer_prefix()`` outputs ``osx_framework_library``. But since ``prefix`` is not available for ``sysconfig.get_default_scheme()``, which is the stdlib replacement for ``_infer_prefix()``, presumably Apple wouldn't be able to magically switch between ``osx_framework_library`` and ``posix_prefix``. ``_infer_prefix()`` returning ``osx_framework_library`` means its behavior is consistent whether we use the stdlib implementation or our own, and we deal with this special case in ``get_scheme()`` instead. """ return ( "osx_framework_library" in _AVAILABLE_SCHEMES and not running_under_virtualenv() and is_osx_framework() ) def _infer_prefix() -> str: """Try to find a prefix scheme for the current platform. This tries: * A special ``osx_framework_library`` for Python distributed by Apple's Command Line Tools, when not running in a virtual environment. * Implementation + OS, used by PyPy on Windows (``pypy_nt``). * Implementation without OS, used by PyPy on POSIX (``pypy``). * OS + "prefix", used by CPython on POSIX (``posix_prefix``). * Just the OS name, used by CPython on Windows (``nt``). If none of the above works, fall back to ``posix_prefix``. """ if _PREFERRED_SCHEME_API: return _PREFERRED_SCHEME_API("prefix") if _should_use_osx_framework_prefix(): return "osx_framework_library" implementation_suffixed = f"{sys.implementation.name}_{os.name}" if implementation_suffixed in _AVAILABLE_SCHEMES: return implementation_suffixed if sys.implementation.name in _AVAILABLE_SCHEMES: return sys.implementation.name suffixed = f"{os.name}_prefix" if suffixed in _AVAILABLE_SCHEMES: return suffixed if os.name in _AVAILABLE_SCHEMES: # On Windows, prefx is just called "nt". return os.name return "posix_prefix" def _infer_user() -> str: """Try to find a user scheme for the current platform.""" if _PREFERRED_SCHEME_API: return _PREFERRED_SCHEME_API("user") if is_osx_framework() and not running_under_virtualenv(): suffixed = "osx_framework_user" else: suffixed = f"{os.name}_user" if suffixed in _AVAILABLE_SCHEMES: return suffixed if "posix_user" not in _AVAILABLE_SCHEMES: # User scheme unavailable. raise UserInstallationInvalid() return "posix_user" def _infer_home() -> str: """Try to find a home for the current platform.""" if _PREFERRED_SCHEME_API: return _PREFERRED_SCHEME_API("home") suffixed = f"{os.name}_home" if suffixed in _AVAILABLE_SCHEMES: return suffixed return "posix_home" # Update these keys if the user sets a custom home. _HOME_KEYS = [ "installed_base", "base", "installed_platbase", "platbase", "prefix", "exec_prefix", ] if sysconfig.get_config_var("userbase") is not None: _HOME_KEYS.append("userbase") def get_scheme( dist_name: str, user: bool = False, home: str | None = None, root: str | None = None, isolated: bool = False, prefix: str | None = None, ) -> Scheme: """ Get the "scheme" corresponding to the input parameters. :param dist_name: the name of the package to retrieve the scheme for, used in the headers scheme path :param user: indicates to use the "user" scheme :param home: indicates to use the "home" scheme :param root: root under which other directories are re-based :param isolated: ignored, but kept for distutils compatibility (where this controls whether the user-site pydistutils.cfg is honored) :param prefix: indicates to use the "prefix" scheme and provides the base directory for the same """ if user and prefix: raise InvalidSchemeCombination("--user", "--prefix") if home and prefix: raise InvalidSchemeCombination("--home", "--prefix") if home is not None: scheme_name = _infer_home() elif user: scheme_name = _infer_user() else: scheme_name = _infer_prefix() # Special case: When installing into a custom prefix, use posix_prefix # instead of osx_framework_library. See _should_use_osx_framework_prefix() # docstring for details. if prefix is not None and scheme_name == "osx_framework_library": scheme_name = "posix_prefix" if home is not None: variables = {k: home for k in _HOME_KEYS} elif prefix is not None: variables = {k: prefix for k in _HOME_KEYS} else: variables = {} paths = sysconfig.get_paths(scheme=scheme_name, vars=variables) # Logic here is very arbitrary, we're doing it for compatibility, don't ask. # 1. Pip historically uses a special header path in virtual environments. # 2. If the distribution name is not known, distutils uses 'UNKNOWN'. We # only do the same when not running in a virtual environment because # pip's historical header path logic (see point 1) did not do this. if running_under_virtualenv(): if user: base = variables.get("userbase", sys.prefix) else: base = variables.get("base", sys.prefix) python_xy = f"python{get_major_minor_version()}" paths["include"] = os.path.join(base, "include", "site", python_xy) elif not dist_name: dist_name = "UNKNOWN" scheme = Scheme( platlib=paths["platlib"], purelib=paths["purelib"], headers=os.path.join(paths["include"], dist_name), scripts=paths["scripts"], data=paths["data"], ) if root is not None: converted_keys = {} for key in SCHEME_KEYS: converted_keys[key] = change_root(root, getattr(scheme, key)) scheme = Scheme(**converted_keys) return scheme def get_bin_prefix() -> str: # Forcing to use /usr/local/bin for standard macOS framework installs. if sys.platform[:6] == "darwin" and sys.prefix[:16] == "/System/Library/": return "/usr/local/bin" return sysconfig.get_paths()["scripts"] def get_purelib() -> str: return sysconfig.get_paths()["purelib"] def get_platlib() -> str: return sysconfig.get_paths()["platlib"]
Save File
Cancel