Class PythonInterpreter

pex/interpreter.py:816–1725

class PythonInterpreter(object):
    _REGEX = re.compile(
        r"""
        ^
        (?:
            python |
            pypy
        )
        (?:
            # Major version
            [2-9]
            (?:.
                # Minor version
                [0-9]+
                # Some distributions include a suffix on the interpreter name, similar to
                # PEP-3149. For example, Gentoo has /usr/bin/python3.6m to indicate it was
                # built with pymalloc
                [a-z]?
            )?
        )?
        {extension}
        $
        """.format(
            extension=re.escape(EXE_EXTENSION)
        ),
        # NB: OSX ships python binaries named Python with a capital-P; so we allow for this as well
        # as accommodating Windows which has DOS case insensitivity.
        flags=re.IGNORECASE | re.VERBOSE,
    )

    _PYTHON_INTERPRETER_BY_NORMALIZED_PATH = {}  # type: Dict

    @classmethod
    @contextmanager
    def _cleared_memory_cache(cls):
        # type: () -> Iterator[None]
        # Intended for test use.

        _cache = cls._PYTHON_INTERPRETER_BY_NORMALIZED_PATH.copy()
        cls._PYTHON_INTERPRETER_BY_NORMALIZED_PATH = {}
        try:
            yield
        finally:
            cls._PYTHON_INTERPRETER_BY_NORMALIZED_PATH = _cache

    @classmethod
    def _resolve_pyvenv_canonical_python_binary(
        cls,
        maybe_venv_python_binary,  # type: str
    ):
        # type: (...) -> Optional[str]
        maybe_venv_python_binary = os.path.abspath(maybe_venv_python_binary)
        if not os.path.islink(maybe_venv_python_binary):
            return None

        pyvenv_cfg = PyVenvCfg.find(maybe_venv_python_binary)
        if pyvenv_cfg is None:
            return None