auto save

o.py

-li=['小','虎','语']
-file=open('C:\\Users\\29018\\Desktop\\test.txt','a',encoding='utf-8') 
-file.writelines(li)
\ No newline at end of file
+file=open('C:\\Users\\29018\\Desktop\\test.txt','w',encoding='utf-8')
+file.write("d")
+file.close()
+
+file=open('C:\\Users\\29018\\Desktop\\test.txt','r',encoding='utf-8')
+'''for i in file:
+    if "d" in i:
+        print("在文件里")'''
+
+lanzi=""
+for i in file:
+    if "d" in i:
+        xin=i.replace("d","o")
+        lanzi=lanzi+xin
+file=open('C:\\Users\\29018\\Desktop\\test.txt','w',encoding='utf-8') 
+file.write(lanzi)
+print(lanzi)
+file.close()
+