python - Go to next iteration after finding string by looping through text file? -

i'm trying iterate through text file organized this:

student 1 name
student 1 grade
student 2 name
student 2 grade
...
student n name
student n grade

once i've found students name on line, how can change grade? here's code i've come with, can't figure out how change line following students name.

gradebook = open('gradebook.txt', 'r')   studentname = input("what students name?") line in gradebook:     if line.rstrip() == studentname:         #i want insert code here change text on line          #after line studentname found.     else:         print("the student not found.") 

 temp = []  open('data', 'r') f:     line in f:         if "student 2" in line:             try:                 # student 2 grade                 line = next(f)                 temp.append(changed_line)               # in case student name last line of file             except stopiteration:                 break         else:              temp.append(line)     # save changes file    open('data', 'w') f:        line in temp:          f.write(line)