auto save

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'
 # 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'
-file1=open(r"C:\Users\Lenovo\Desktop\新建文件夹\lk.txt","w",encoding="utf-8")
-file1.write("小兰:12")
-file1.write("小丽:11")
-file1.write("李文:9")
-file1.close()
+# file1=open(r"C:\Users\Lenovo\Desktop\新建文件夹\lk.txt","w",encoding="utf-8")
+# file1.write("小兰:12")
+# file1.write("小丽:11")
+# file1.write("李文:9")
+# file1.close()
\ No newline at end of file
+
+# with open (r"C:\Users\Lenovo\Desktop\新建文件夹\lk.txt","a",encoding="utf-8") as file1: 
+#     file1.write("小兰:12")
+new_data=''
+with open (r"C:\Users\Lenovo\Desktop\新建文件夹\lk.txt","r",encoding="utf-8") as file1: 
+    for data in file1:
+        if "小兰:12" in data:
+            data=data.replace("小兰:12","小兰:10")
+        new_data+=data
+with open (r"C:\Users\Lenovo\Desktop\新建文件夹\lk.txt","w",encoding="utf-8") as file1: 
+    file1.write()
+