save project

diy.py

-file=open ("book.txt","r",encoding="utf=8")
-for data in file:
-    if '小兰:10本'in data:
-        print('在')
-    else:
-        print('不在')
-    if'小强:12本'in data:
-        print('在')
-    else:
-         print('不在')   
\ No newline at end of file
+new_data=""
+with open ("book.txt","r",encoding="utf=8")
+    for data in file:
+        if '小赤:10本'in data:
+            data=data.replace(_old:'小赤:10本',_new'小赤：20')
+        if '小橙:11本'in data:
+            data=data.replace(_old:'小橙:11本',_new'小橙：21')
+            data=data.replace(_old:'小赤:10本',_new'小赤：20')
+            new_ data+data 
+with open ("book.txt","w",encoding="utf=8")as f1  
+    f1.wite(new_data)
+with open ("book.txt","w",encoding="utf=8")as f2  
+    a=f2.read()
+    print(a)
\ No newline at end of file