Create a binary file with roll number, name and marks. Input a roll number and update the marks

def update_marks(rollno):
  with open('data.txt', 'r') as f:
    data = f.read()
  data = data.split('\n')
  for i in range(len(data)):
    data[i] = data[i].split()
    if data[i][0] == rollno:
      data[i][2] = input('Enter new marks: ')
  with open('data.txt', 'w') as f:
    for i in data:
      f.write(' '.join(i) + '\n')
 
update_marks('101')