python - Reset time part of a pandas timestamp

Question

How can I reset the time part of a pandas timestamp?

I want to reset time part in value of pandas.Timestamp.
I guess I can do it using the following procedure.

• step 1) Timestamp to datetime type
• step 2) datetime to seconds
• step 3) truncate time part in seconds
• step 4) bring back seconds to Timestamp

Even if my guess is correct, it takes too long to do. Is there a straightforward way to achieve this goal?

In [371]: ts = pd.Timestamp('2014/11/12 13:35')

In [372]: ts

Out[372]: Timestamp('2014-11-12 13:35:00')

In [373]: ts.hour = 0 # <-- this is what I am trying to do.

Answer 1

I think you are looking for the replace method (see docs):

In [18]: ts
Out[18]: Timestamp('2014-11-12 13:35:00')

In [19]: ts.replace(hour=0)
Out[19]: Timestamp('2014-11-12 00:35:00')

This is a method inherited from datetime.datetime

If you want to reset the full time part, you specify all parts in replace:

In [20]: ts.replace(hour=0, minute=0, second=0)
Out[20]: Timestamp('2014-11-12 00:00:00')

There is also a DatetimeIndex.normalize method, but this isn't available on the individual Timestamps (I opened an issue for that: https://github.com/pydata/pandas/issues/8794):

In [21]: pd.DatetimeIndex([ts]).normalize()[0]
Out[21]: Timestamp('2014-11-12 00:00:00')