原始的字符串为['cat','goat','cat]
输入一个新动物名字，如果名字在字符串内，就remove这个名字；如果不在就新加进去
要求用到的函数有def and return, using print output, input, if, in keywords, .append(), .pop(), .remove() list methods.
新人刚刚入门就卡壳了
def get_anname():
anni_name = input("Please input the name of annimal you want check:")
L = ['cat','goat','cat']
if anni_name in L :
L.remove(anni_name)
else :
L.append(anni_name)
return L
