diy.py

with open(r'c:\Users\Administrator\Documents\lesson13-1\sales_list.txt','r',encoding='utf-8') as file:
    a=file.readline()
final_sum=[]
for i in a:
    data=i.split()
    print(data[1:])
    sum=0
    for sales in data[1:]:
        sum=sum+sales
    result=data[0]+str(sum)='\n'
    final_sum.append(result)

with open(r'c:\Users\Administrator\Documents\lesson13-1\sales_list.txt','a',encoding='utf-8') as file:
    file.writelines(final_sum)