Copying column values up based on other column values

[Codeliner]

Hello,

I have this dataframe

import numpy as np
import pandas as pd
from numpy.random import randn
df=pd.DataFrame(randn(5,4),['A','B','C','D','E'],['W','X','Y','Z'])


W X Y Z
A -0.183141 -0.398652 0.909746 0.332105
B -0.587611 -2.046930 1.446886 0.167606
C 1.142661 -0.861617 -0.180631 1.650463
D 1.174805 -0.957653 1.854577 0.335818
E -0.680611 -1.051793 1.448004 -0.490869

is there a way to create a column S - which will copy column column Y values UP- if values in column Y are above 1 - otherwise return new value above zero?.I made this manually:

S:

A 1.446886
B 1.446886
C 1.854577
D 1.854577
E 1.448004


thanks a lot!