# 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'
# a=open(r'D:\DESK\test.txt',"w",encoding="utf-8")
# a.write("小丽：11本")
# a.write("张伟：16本\n")
# with open(r'D:\DESK\test.txt',"a",encoding="utf-8") as a:
#     a.write("小兰：12本\n")
# with open(r'D:\DESK\test.txt',"r",encoding="utf-8") as a:
#     for data in a:
#         if "小兰：12本" in data:
#             print("数据在文件中")
new_data=""
with open(r'D:\DESK\test.txt',"r",encoding="utf-8") as a:
    for data in a:
        data=data.replace("小兰：12本","小兰：14本")
        new_data+=data
print(new_data)