在Python中从txt文件中删除数据

Question

I have a txt file open in python which data has been written to. I need a way for only 3 parts of data to be inputted into this file before the oldest bit of data is deleted and replaced with the newer data.

For example: A teacher has asked me to build a system in python that askes students 10 random maths questions, before talking this quiz the student must enter their name and class number.

When the quiz has been completed their name and score must be written to a certain file, class1.txt if they belong to class 1, class2.txt if they belong to class2 and so on.

This system is working correctly but the teacher has now asked me if it's possible for only the 3 most recent quiz results to be stored in the corresponding file.

Thanks a lot A GCSE student who's bricking himself

Answer 1

You could use collections.deque like this:

from collections import deque

with open("file.txt", "r+") as f:
    d = deque(f, 3)
    d.append(new_score)  # or use appendleft()
    f.seek(0)
    f.truncate()
    f.writelines(d)