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'
# with open(r'D:\chenziyu\ct.txt','a',encoding='utf-8') as file1:
#     file1.write('小兰:12本\n')
#     file1.write('小丽:11本\n')
#     file1.write('李文:9本\n')
#     file1.write('张伟:16本\n')
#     file1.write('阿杰:14本\n')
#     file1.write('彬彬:15本\n')
#     file1.close()
# with open(r'D:\chenziyu\ct.txt','r',encoding='utf-8') as file1:
#    for data in file1:
#        if '小兰:12本' in data:
#            print('小兰在文件中')
#        if '小丽:11本' in data:
#            print('小丽在文件中')  
new_data=''
with open(r'D:\chenziyu\ct.txt','r',encoding='utf-8') as file1:
    for data in file1:
        if '小兰:12本' in data:
            data=data.replace('小兰:12本','小兰:14本')
        if '小丽:11本' in data: 
            data=data.replace('小丽:11本','小丽:13本')
        new_data +=data
with open(r'D:\chenziyu\ct.txt','w',encoding='utf-8') as file1:
    file1.write(new_data)
with open(r'D:\chenziyu\ct.txt','r',encoding='utf-8') as file1:
    a=file1.read()
    print(a)