PYTHON 寫函數，檢查傳入字典的每一個value的長度,如果大於2，那么僅保留前兩個長度的內容，並將新內容返回給調用者

def a4(arg):
    ret = {}
    for key,value in arg.items():
        if len(value) > 2:
            ret[key] = value[0:2]
        else:
            ret[key] = value
    return  ret

dic = {"k1": "v1v1", "k2": [11, 22, 33, 44],"k3":"12"}
r = a4(dic)
print(r)