将表达式作为命名参数nam传递

Question

我使用的是dateutil.relativedelta()，它在我的age-元组中有与time_unit相对应的命名参数，得到相对时间的代码如下所示：

def time_delta(age):
    now = datetime.fromtimestamp(int(time.time()))
    if age.time_unit == "seconds":
        relative_time = now - relativedelta(seconds=int(age.value))
    elif age.time_unit == "minutes":
        relative_time = now - relativedelta(minutes=int(age.value))
    elif age.time_unit == "hours":
        relative_time = now - relativedelta(hours=int(age.value))
    elif age.time_unit == "days":
        relative_time = now - relativedelta(days=int(age.value))
    elif age.time_unit == "weeks":
        relative_time = now - relativedelta(weeks=int(age.value))
    elif age.time_unit == "months":
        relative_time = now - relativedelta(months=int(age.value))
    elif age.time_unit == "years":
        relative_time = now - relativedelta(years=int(age.value))

在Python2.7中，有没有什么方法可以让它成为一个单行线，而不是使用以下代码：

^{pr2}$

上面没用。我是坚持使用if/elif还是有更好的方法可以做？在

Answer 1

def time_delta(age):
    now = datetime.fromtimestamp(int(time.time()))
    return now - relativedelta(**{age.time_unit: int(age.value)})

（代码没有测试，但可能会起作用）

Answer 2

def time_delta(age):
    now = datetime.fromtimestamp(int(time.time()))
    if age.time_unit in ["seconds","minutes","hours","days","weeks","months","years"]:
        exec("relative_time = now - relativedelta({}=int(age.value))".format(age.time_unit))

我知道，我知道。exec！！！在这种模式下很安全，伙计们。在

编辑：打字错误。exec，而不是{}