Class _ScriptTarget

Lib/pdb.py:188–242

class _ScriptTarget(_ExecutableTarget):
    def __init__(self, target):
        self._check(target)
        self._target = self._safe_realpath(target)

        # If PYTHONSAFEPATH (-P) is not set, sys.path[0] is the directory
        # of pdb, and we should replace it with the directory of the script
        if not sys.flags.safe_path:
            sys.path[0] = os.path.dirname(self._target)

    @staticmethod
    def _check(target):
        """
        Check that target is plausibly a script.
        """
        if not os.path.exists(target):
            print(f'Error: {target} does not exist')
            sys.exit(1)
        if os.path.isdir(target):
            print(f'Error: {target} is a directory')
            sys.exit(1)

    @staticmethod
    def _safe_realpath(path):
        """
        Return the canonical path (realpath) if it is accessible from the userspace.
        Otherwise (for example, if the path is a symlink to an anonymous pipe),
        return the original path.

        See GH-142315.
        """
        realpath = os.path.realpath(path)
        return realpath if os.path.exists(realpath) else path

    def __repr__(self):
        return self._target

    @property
    def filename(self):
        return self._target

    @property
    def code(self):
        # Open the file each time because the file may be modified
        with io.open_code(self._target) as fp:
            return f"exec(compile({fp.read()!r}, {self._target!r}, 'exec'))"

    @property
    def namespace(self):
        return dict(
            __name__='__main__',
            __file__=self._target,
            __builtins__=__builtins__,
            __spec__=None,
        )


class _ModuleTarget(_ExecutableTarget):