auto save

diy.py

@@ -3,12 +3,18 @@
 #file1.write("小兰：12本'\n'李文：9本'\n'张伟：16本")
 #file1.close()
 
-with open(r"C:\Users\HP\Desktop\新建文件夹\test.txt","r",encoding="utf-8") as file1:
+abc=""
+
+with open(r"C:\Users\HP\Desktop\新建文件夹\test.txt","w",encoding="utf-8") as file1:
     #把文件里面的内容遍历在控制台
     #判断小兰：12本在不在里边，在的话打印“数据在里面”出控制台
-    for i in file1:
-        print(i)
-    if '小兰：12本' in file1:
-        print("数据在里面")
+    file1.write("小兰：12本'\n'李文：9本'\n'张伟：16本")
+    for data in file1:
+        if '小兰：12本' in data:
+            data=data.replace("小兰:12本","小兰:15本")
+        abc+=data
+#创建空的字符串变量，修改里边的数据,最后能够打印出新的内容出来
+with open(r"C:\Users\HP\Desktop\新建文件夹\test.txt","w",encoding="utf-8") as file1:
+    file1.write(abc)