def if_else(self, true_expr, false_expr):
        """Returns either ``true_expr`` or ``false_expr`` depending on the
        value of this expression, which must resolve to a boolean.

        Examples::

            import fiftyone as fo
            import fiftyone.zoo as foz
            from fiftyone import ViewField as F

            dataset = foz.load_zoo_dataset("quickstart")

            # Set `uniqueness` values below 0.75 to None
            view = dataset.set_field(
                "uniqueness",
                (F("uniqueness") > 0.75).if_else(F("uniqueness"), None)
            )

            print(view.bounds("uniqueness"))

        Args:
            true_expr: a :class:`ViewExpression` or MongoDB expression dict
            false_expr: a :class:`ViewExpression` or MongoDB expression dict

        Returns:
            a :class:`ViewExpression`
        """
        return ViewExpression(
            {"$cond": {"if": self, "then": true_expr, "else": false_expr}}
        )
Returns either ``true_expr`` or ``false_expr`` depending on the
        value of this expression, which must resolve to a boolean.

        Examples::

            import fiftyone as fo
            import fiftyone.zoo as foz
            from fiftyone import ViewField as F

            dataset = foz.load_zoo_dataset("quickstart")

            # Set `uniqueness` values below 0.75 to None
            view = dataset.set_field(
                "uniqueness",
                (F("uniqueness") > 0.75).if_else(F("uniqueness"), None)
            )

            print(view.bounds("uniqueness"))

        Args:
            true_expr: a :class:`ViewExpression` or MongoDB expression dict
            false_expr: a :class:`ViewExpression` or MongoDB expression dict

        Returns:
            a :class:`ViewExpression`
        
fiftyone/core/expressions.py