How to get previous non empty value of another column

[klllmmm]

Managed to do this

table['CustName'].replace('', np.nan,  inplace=True)

table['CustName'].fillna(method ='pad',  inplace=True)

Output:
     CustName  Value
0  Customer A   1500
1  Customer A   1400
2  Customer A   9000
3  Customer B   9000
4  Customer B   9000
5  Customer B   1600