'Checks if a partition is less than the other.
Examples
>>> from sympy.combinatorics.partitions import Partition
>>> a = Partition([1, 2], [3, 4, 5])
>>> b = Partition([1], [2, 3], [4], [5])
>>> a.rank, b.rank
(9, 34)
>>> a < b
True'

def __lt__(self, other):

    return (self.sort_key() < sympify(other).sort_key())
