diy.py

with open(r'c:\Users\Administrator\Documents\lesson13-1\sales_list.txt','r',encoding='utf-8')as file:
    a=file.readlines()
    #print(a)
final_s=[]
for i in a:#用foy...in...把
    data=i.split()
    s=0
    for sales in data[1:]:
        s=s+int(sales)
    result=data[0]+str(s)+'\n'
    final_s.append(result)
with open(r'c:\Users\Administrator\Documents\lesson13-1\sales_list.txt','a',encoding='utf-8')as file:
     file.writelines(final_s)