list1 = list('ABCDEF')
list2 = []

print("Before:")
print("list1=", list1)
print("list2=", list2)
print("")

print("copying:")
while list1:
    list2.append(list1.pop(0))
    print("list2=", list2)
    print("list1=", list1)
    print("")

print("After:")
print("list1=", list1)
print("list2=", list2)