save project

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'
+new_i=""
 with open(r'C:\Users\50639\Desktop\book.txt', 'w',encoding='utf-8') as d:
+    d.write("小兰:12本\n"+"小丽:11本\n"+"'李文:9本\n"+"张伟:16本\n")
+with open(r'C:\Users\50639\Desktop\book.txt', 'r',encoding='utf-8') as d:
     for i in d:
-        if "小兰:12本" in i:
-            i.replace()
-        
+        if '小兰:12本' in i:
+            i=i.replace('小兰:12本','小兰:14本')
+            
+        new_i+=i
+    
+with open(r'C:\Users\50639\Desktop\book.txt', 'w',encoding='utf-8') as s:
+    s.write(new_i)