CODEWITHSUNDEEP
pythondatetime
Ryan Saxe
Ryan Saxe

Reputation: 17839

How to determine if a variable is a datetime object?

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

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')

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'

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'?

Upvotes: 83

Views: 166370

Answers (8)

AkshayB
AkshayB

Reputation: 55

This worked for me in python 3.9.4

if type(timeIn) is type(datetime.now().time()):

Upvotes: 1

Artur Barseghyan
Artur Barseghyan

Reputation: 14172

Note, that datetime.date objects are not considered to be of datetime.datetime type, while datetime.datetime objects are considered to be of datetime.date type.

import datetime                                                                                                                     

today = datetime.date.today()                                                                                                       
now = datetime.datetime.now()                                                                                                       

isinstance(today, datetime.datetime)                                                                                                
>>> False

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

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

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

Upvotes: 6

toast38coza
toast38coza

Reputation: 9066

You can also check using duck typing (as suggested by James).

Here is an example:

from datetime import date, datetime

def is_datetime(dt):
    """
    Returns True if is datetime
    Returns False if is date
    Returns None if it is neither of these things
    """
    try:
        dt.date()
        return True
    except:
        if isinstance(dt, date):
            return False
    return None

Results: 

In [8]: dt = date.today()
In [9]: tm = datetime.now()
In [10]: is_datetime(dt)
Out[11]: False
In [12]: is_datetime(tm)
Out[13]: True
In [14]: is_datetime("sdf")
In [15]:

Upvotes: 3

RichieHindle
RichieHindle

Reputation: 281495

You need isinstance(variable, datetime.datetime):

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

Update

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

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

Pandas Timestamp

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

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)

Upvotes: 177

Saurav Kumar
Saurav Kumar

Reputation: 583

I believe all the above answer will work only if date is of type datetime.datetime. What if the date object is of type datetime.time or datetime.date?

This is how I find a datetime object. It always worked for me. (Python2 & Python3):

import datetime
type(date_obj) in (datetime, datetime.date, datetime.datetime, datetime.time)

Testing in Python2 or Python3 shell:

import datetime
d = datetime.datetime.now()  # creating a datetime.datetime object.
date = d.date()  # type(date): datetime.date
time = d.time()  # type(time): datetime.time

type(d) in (datetime, datetime.date, datetime.datetime, datetime.time)
True
type(date) in (datetime, datetime.date, datetime.datetime, datetime.time)
True
type(time) in (datetime, datetime.date, datetime.datetime, datetime.time)
True

Upvotes: 5

James
James

Reputation: 2795

While using isinstance will do what you want, it is not very 'pythonic', in the sense that it is better to ask forgiveness than permission. 

try:
    do_something_small_with_object() #Part of the code that may raise an 
                                     #exception if its the wrong object
except StandardError:
    handle_case()

else:
    do_everything_else()

Upvotes: 2

TehTris
TehTris

Reputation: 3217

isinstance is your friend

>>> thing = "foo"
>>> isinstance(thing, str)
True

Upvotes: 3

korylprince
korylprince

Reputation: 3009

Use isinstance.

if isinstance(variable,datetime.datetime):
    print "Yay!"

Upvotes: 9

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