save project

diy.py

 with open(r'C:\Users\Administrator\Desktop\sales_list.txt','r',encoding='utf-8')as file:
     a=file.readlines()
+
+final=[]
 for i in a:
     data=i.split()
     # print(data[1:])
     sum=0
     for sales in data[1:]:
         sum=sum+int(sales)
-    r=data[0]+str(sum)
-    print(r)
+    r=data[0]+str(sum)+'\n'
+    final.append(r)
+    
+with open(r'C:\Users\Administrator\Desktop\sales_list.txt','a',encoding='utf-8') as file:
+    file.writelines(final)
+