diy.py

# 写入同学们的捐赠明细：'小兰：12本'、'小丽：11本'、'李文：9本'、'张伟：16本'
new_date = ""
with open(r"C:\Users\Windows 10\Desktop\book.txt","r",encoding="utf-8") as file:
    for date in file:
        if "小强：12本" in date:
            date.replace("小强：12本","小强：11本")
        if "小兰：12本" in date:
            date.replace("小兰：12本","小兰：14本")
        new_date += date
with open(r"C:\Users\Windows 10\Desktop\book.txt","w",encoding="utf-8") as file:
     file.write(new_date)