DataFrame.
lt
Compare if the current value is less than the other.
>>> df = ps.DataFrame({'a': [1, 2, 3, 4], ... 'b': [1, np.nan, 1, np.nan]}, ... index=['a', 'b', 'c', 'd'], columns=['a', 'b'])
>>> df.lt(1) a b a False False b False False c False False d False False