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

importstruct

 

defcreate_binary_file_with_marks(filename):

data = [(1, "Alice", 85), (2, "Bob", 90), (3, "Charlie", 78)]

with open(filename, 'wb') as file:

forroll_number, name, marks in data:

file.write(struct.pack('I20sI', roll_number, name.encode(), marks))

 

defupdate_marks_in_binary_file(filename, roll_number, new_marks):

with open(filename, 'r+b') as file:

while True:

try:

roll_number_bytes, name_bytes, marks_bytes = struct.unpack('I20sI', file.read(28))

ifroll_number == struct.unpack('I', roll_number_bytes)[0]:

file.seek(-4, 1)  # Move back 4 bytes to overwrite marks

file.write(struct.pack('I', new_marks))

print("Marks updated successfully.")

return

exceptstruct.error:

print("Roll number not found.")

return

 

if __name__ == "__main__":

filename = "students_marks.bin"

create_binary_file_with_marks(filename)

roll_number_to_update = int(input("Enter roll number to update: "))

new_marks = int(input("Enter new marks: "))

update_marks_in_binary_file(filename, roll_number_to_update, new_marks)