Saving an index from a list in a while loop in Python

Question

How do you save an index of a list while in a 'while' loop?

Basically I am running through a text file and I want to identify a date, and then afterwards get the information that corresponds to that date which is the line below. So far I can match the date entered to the line with that date but don't know how to save that line so I can get he information from the line below.

f = open("studentinfo.txt")
#ask for date
d = input("Enter the date:")
date = [d]
#check to see if date is avialable
while True:
    line = f.readline().split()
    if line:
        if line == date:
            print(line)
            #save data in here, index etc
    else:
        break
        print("No data available")

Answer 1

How do you save an index of a list while in a 'while' loop. Basically I am running through a text file and I want to identify a date, and then afterwards get the information that corresponds to that date which is the line below. So far I can match the date entered to the line with that date but don't know how to save that line so I can get he information from the line below.

f = open("studentinfo.txt")
#ask for date
d = input("Enter the date:")
date = [d]
#check to see if date is avialable

for i, line in enumerate(f.readlines()):
    if line:
        if line == date:
            print(line)
            #save data in here, index etc
    else:
        break
        # print("No data available") <-- check indents unreachable code

Answer 2

You have to track the index manually, ie:

i = 0
while True:
    # Do stuff.
    i += 1