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'
import textwrap
#with open("D:\\ni.txt","w",encoding="utf-8") as nihao:
    #nihao.write("小兰：12本\n小丽：11本\n李文：9本\n张伟：16本")
gou=open("D:\\ni.txt","r",encoding="utf-8")
new=""
for a in gou:
    if "小兰:12本" in gou:
        print("hao")
        gou.replace("小兰：12本","小兰：16本")
        new+=a
with open("D:\\ni.txt","w",encoding="utf-8") as gou:
    gou.write(new)