import pandas as pd

df = {  'Column1': ["A","B","C","D","E"],
        'Column2': ["Keep","Keep","Erase","Erase","Keep"]}
df = pd.DataFrame(df, columns=['Column1','Column2'])



def func(any_column):
    df[any_column][df['Column2'].isin(['Erase'])] = ""
    return any_column

df['Column1'] = df['Column1'].map(func)
df