diy.py

# 写入同学们的捐赠明细：'小兰：12本'、'小丽：11
with open(r"C:\Users\Administrator\Desktop\book.txt","a",encoding='utf-8') as s1:
    for data in s1；
        if "小强:10本" in data:
            print("小强:11本")
            data=data.replace('小强:11本','小强:14本')
        new_data +=data

with open(r"C:\Users\Administrator\Desktop\book.txt","w",encoding='utf-8') as s1:
s1=write(new_data)