diy.py

with open(r"c:\Users\EDZ\Documents\lesson13-1\sales_list.txt","r",encoding="utf-8") as file:
    a=file.readlines()
#print(a)
aasum=[]

for i in a:
    
    www=i.split()
    #print(www[0])
    #print(www[1:])
    sum=0
    for sales in www[1:]:
        sum=sum+int(sales)
    qq=www[0]+str(sum)+"\n"
    aasum.append(qq)
 with open(r"c:\Users\EDZ\Documents\lesson13-1\sales_list.txt","a",encoding="utf-8") as file:   
    file.writelines(aasum)