Convert date to datetime in Python

Solution 1:

You can use datetime.combine(date, time); for the time, you create a datetime.time object initialized to midnight.

from datetime import date
from datetime import datetime

dt = datetime.combine(date.today(), datetime.min.time())

Solution 2:

There are several ways, although I do believe the one you mention (and dislike) is the most readable one.

>>> t=datetime.date.today()
>>> datetime.datetime.fromordinal(t.toordinal())
datetime.datetime(2009, 12, 20, 0, 0)
>>> datetime.datetime(t.year, t.month, t.day)
datetime.datetime(2009, 12, 20, 0, 0)
>>> datetime.datetime(*t.timetuple()[:-4])
datetime.datetime(2009, 12, 20, 0, 0)

and so forth -- but basically they all hinge on appropriately extracting info from the date object and ploughing it back into the suitable ctor or classfunction for datetime.

Solution 3:

The accepted answer is correct, but I would prefer to avoid using datetime.min.time() because it's not obvious to me exactly what it does. If it's obvious to you, then more power to you. I also feel the same way about the timetuple method and the reliance on the ordering.

In my opinion, the most readable, explicit way of doing this without relying on the reader to be very familiar with the datetime module API is:

from datetime import date, datetime
today = date.today()
today_with_time = datetime(
    year=today.year, 
    month=today.month,
    day=today.day,
)

That's my take on "explicit is better than implicit."

Solution 4:

You can use the date.timetuple() method and unpack operator *.

args = d.timetuple()[:6]
datetime.datetime(*args)

Solution 5:

Today being 2016, I think the cleanest solution is provided by pandas Timestamp:

from datetime import date
import pandas as pd
d = date.today()
pd.Timestamp(d)

Timestamp is the pandas equivalent of datetime and is interchangable with it in most cases. Check:

from datetime import datetime
isinstance(pd.Timestamp(d), datetime)

But in case you really want a vanilla datetime, you can still do:

pd.Timestamp(d).to_datetime()

Timestamps are a lot more powerful than datetimes, amongst others when dealing with timezones. Actually, Timestamps are so powerful that it's a pity they are so poorly documented...