관리-도구

편집 파일: discover.py

from __future__ import absolute_import, unicode_literals

from abc import ABCMeta, abstractmethod

from six import add_metaclass

@add_metaclass(ABCMeta)
class Discover(object):
    """Discover and provide the requested Python interpreter"""

@classmethod
    def add_parser_arguments(cls, parser):
        """Add CLI arguments for this discovery mechanisms.

:param parser: the CLI parser
        """
        raise NotImplementedError

# noinspection PyUnusedLocal
    def __init__(self, options):
        """Create a new discovery mechanism.

:param options: the parsed options as defined within :meth:`add_parser_arguments`
        """
        self._has_run = False
        self._interpreter = None
        self._env = options.env

@abstractmethod
    def run(self):
        """Discovers an interpreter.

:return: the interpreter ready to use for virtual environment creation
        """
        raise NotImplementedError

@property
    def interpreter(self):
        """
        :return: the interpreter as returned by :meth:`run`, cached
        """
        if self._has_run is False:
            self._interpreter = self.run()
            self._has_run = True
        return self._interpreter