list.append 報錯 bhl.append('9')報錯，但我用交互模式正常

bhl=list
bh = list(input("輸入3位字符："))
if len(bh)==3:
    for bhs in bh:
        if(bhs)=="0":
            bhl.append('9')
        elif (bhs)=="1":
            bhs="8"
        elif (bhs)=="2":
            bhs="7"
        elif (bhs) == "3":
            bhs="6"
        elif (bhs)=="4":
            bhs="5"
        elif (bhs)=="5":
            bhs="4"
        elif (bhs)=="6":
            bhs="3"
        elif (bhs)=="7":
            bhs="2"
        elif (bhs)=="8":
            bhs="1"
        elif (bhs)=="9":
            bhs="0"
            
        print(bhl)

else:
    print("輸入字符串數(shù)量不符")