Enter a date by a loop

I want a loop to check for 'FirstName" if first name is there, then enter an end date put in by the end user. If no first name, stop loop.

import pandas as pd
df = pd.read_excel('file.xls')
print('Please enter the end date')
eDate = input()
new_date = pd.to_datetime(eDate)
df.loc[i,'EndDate']

Where I have 'i', I want that to be my if statement result. I'm not sure how to write the if statement