Method __init__

lib/sqlalchemy/sql/schema.py:4485–4540

r"""Create a SQL constraint. :param name: Optional, the in-database name of this ``Constraint``. :param deferrable: Optional bool. If set, emit DEFERRABLE or NOT DEFERRABLE when issuing DDL for this constraint. :param initially: Opt

(
        self,
        name: _ConstraintNameArgument = None,
        deferrable: Optional[bool] = None,
        initially: Optional[str] = None,
        info: Optional[_InfoType] = None,
        comment: Optional[str] = None,
        _create_rule: Optional[Any] = None,
        _type_bound: bool = False,
        **dialect_kw: Any,
    )

    _column_flag: bool

    def __init__(
        self,
        name: _ConstraintNameArgument = None,
        deferrable: Optional[bool] = None,
        initially: Optional[str] = None,
        info: Optional[_InfoType] = None,
        comment: Optional[str] = None,
        _create_rule: Optional[Any] = None,
        _type_bound: bool = False,
        **dialect_kw: Any,
    ) -> None:
        r"""Create a SQL constraint.

        :param name:
          Optional, the in-database name of this ``Constraint``.

        :param deferrable:
          Optional bool.  If set, emit DEFERRABLE or NOT DEFERRABLE when
          issuing DDL for this constraint.

        :param initially:
          Optional string.  If set, emit INITIALLY <value> when issuing DDL
          for this constraint.

        :param info: Optional data dictionary which will be populated into the
            :attr:`.SchemaItem.info` attribute of this object.

        :param comment: Optional string that will render an SQL comment on
          foreign key constraint creation.

            .. versionadded:: 2.0

        :param \**dialect_kw:  Additional keyword arguments are dialect
            specific, and passed in the form ``<dialectname>_<argname>``.  See
            the documentation regarding an individual dialect at
            :ref:`dialect_toplevel` for detail on documented arguments.

        :param _create_rule:
          used internally by some datatypes that also create constraints.

        :param _type_bound:
          used internally to indicate that this constraint is associated with
          a specific datatype.

        """

        self.name = name
        self.deferrable = deferrable
        self.initially = initially
        if info:
            self.info = info
        self._create_rule = _create_rule
        self._type_bound = _type_bound
        util.set_creation_order(self)
        self._validate_dialect_kwargs(dialect_kw)
        self.comment = comment

    def _should_create_for_compiler(