import random
dicelist = [5,1,4,4,2]                # ➊
print("old dicelist:")
print(" a  b  c  d  e")               # ➋
print(dicelist)
text = "Type letter(s) of dice you want to keep and press ENTER "
command = input(text)                 # ➌        
if not "a" in command:                # ➍
    dicelist[0] = random.randint(1,6) # ➎
if not "b" in command:
    dicelist[1] = random.randint(1,6)
if not "c" in command:
    dicelist[2] = random.randint(1,6)
if not "d" in command:
    dicelist[3] = random.randint(1,6)
if not "e" in command:
    dicelist[4] = random.randint(1,6)
print("new dicelist:", dicelist)