检测变量是否为日期时间对象 [英] Detect if a variable is a datetime object

问题描述

我有一个变量，我需要知道它是否是一个日期时间对象。

I have a variable and I need to know if it is a datetime object.

到目前为止，我一直在该函数中使用以下技巧来检测日期时间对象：

So far I have been using the following hack in the function to detect datetime object:

if 'datetime.datetime' in str(type(variable)):
     print('yes')

但实际上应该有一种方法可以检测出某种物体。就像我可以做的一样：

But there really should be a way to detect what type of object something is. Just like I can do:

if type(variable) is str: print 'yes'

除了将对象类型的名称转换为字符串并查看字符串是否包含'datetime.datetime'？

Is there a way to do this other than the hack of turning the name of the object type into a string and seeing if the string contains 'datetime.datetime'?

推荐答案

您需要 isinstance（变量，datetime.datetime）：

>>> import datetime
>>> now = datetime.datetime.now()
>>> isinstance(now, datetime.datetime)
True

更新

达沃斯注意到， datetime.datetime 是 datetime.date ，这意味着以下内容也可以使用：

As noticed by Davos, datetime.datetime is a subclass of datetime.date, which means that the following would also work:

>>> isinstance(now, datetime.date)
True

也许最好的方法只是测试类型（如达沃斯建议的那样）：

Perhaps the best approach would be just testing the type (as suggested by Davos):

>>> type(now) is datetime.date
False
>>> type(now) is datetime.datetime
True

熊猫 Timestamp

Pandas Timestamp

有一条评论提到在python3.7中，此答案中的原始解决方案返回 False （在python3.4中工作正常）。在这种情况下，按照达沃斯的评论，您可以执行以下操作：

One comment mentioned that in python3.7, that the original solution in this answer returns False (it works fine in python3.4). In that case, following Davos's comments, you could do following:

>>> type(now) is pandas.Timestamp

如果要检查某项是否为 datetime.datetime 或 pandas.Timestamp ，只需检查两者

If you wanted to check whether an item was of type datetime.datetime OR pandas.Timestamp, just check for both

>>> (type(now) is datetime.datetime) or (type(now) is pandas.Timestamp)

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