save project

diy.py

@@ -2,3 +2,6 @@
 file=open(r"C:\Users\Public\Desktop\book.txt","w",encoding="utf-8")
 file.write("小兰:12本,小丽:11本,李文:9本,张伟:16本")
 file.close()
+
+with open(r"C:\Users\Public\Desktop\book.txt","a",encoding="utf-8") as file:
+    file.write("小兰:12本\n")
\ No newline at end of file