Boolean

Expr.all(*[, ignore_nulls])	Return whether all values in the column are True.
Expr.any(*[, ignore_nulls])	Return whether any of the values in the column are True.
Expr.has_nulls()	Check whether the expression contains one or more null values.
Expr.is_between(lower_bound, upper_bound[, ...])	Check if this expression is between the given lower and upper bounds.
Expr.is_duplicated()	Return a boolean mask indicating duplicated values.
Expr.is_finite()	Returns a boolean Series indicating which values are finite.
Expr.is_first_distinct()	Return a boolean mask indicating the first occurrence of each distinct value.
Expr.is_in(other)	Check if elements of this expression are present in the other Series.
Expr.is_infinite()	Returns a boolean Series indicating which values are infinite.
Expr.is_last_distinct()	Return a boolean mask indicating the last occurrence of each distinct value.
Expr.is_nan()	Returns a boolean Series indicating which values are NaN.
Expr.is_not_nan()	Returns a boolean Series indicating which values are not NaN.
Expr.is_not_null()	Returns a boolean Series indicating which values are not null.
Expr.is_null()	Returns a boolean Series indicating which values are null.
Expr.is_unique()	Get mask of unique values.
Expr.not_()	Negate a boolean expression.