Class Script

alembic/script/base.py:802–1063

Represent a single revision file in a ``versions/`` directory. The :class:`.Script` instance is returned by methods such as :meth:`.ScriptDirectory.iterate_revisions`.

class Script(revision.Revision):
    """Represent a single revision file in a ``versions/`` directory.

    The :class:`.Script` instance is returned by methods
    such as :meth:`.ScriptDirectory.iterate_revisions`.

    """

    def __init__(
        self,
        module: ModuleType,
        rev_id: str,
        path: Union[str, os.PathLike[str]],
    ):
        self.module = module
        self.path = _preserving_path_as_str(path)
        super().__init__(
            rev_id,
            module.down_revision,
            branch_labels=util.to_tuple(
                getattr(module, "branch_labels", None), default=()
            ),
            dependencies=util.to_tuple(
                getattr(module, "depends_on", None), default=()
            ),
        )

    module: ModuleType
    """The Python module representing the actual script itself."""

    path: str
    """Filesystem path of the script."""

    @property
    def _script_path(self) -> Path:
        return Path(self.path)

    _db_current_indicator: Optional[bool] = None
    """Utility variable which when set will cause string output to indicate
    this is a "current" version in some database"""

    @property
    def doc(self) -> str:
        """Return the docstring given in the script."""

        return re.split("\n\n", self.longdoc)[0]

    @property
    def longdoc(self) -> str:
        """Return the docstring given in the script."""

        doc = self.module.__doc__
        if doc:
            if hasattr(self.module, "_alembic_source_encoding"):
                doc = doc.decode(  # type: ignore[attr-defined]
                    self.module._alembic_source_encoding
                )
            return doc.strip()