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Pandas datetime column to ordinal

I'm trying to create a new Pandas dataframe column with ordinal day from a datetime column:

import pandas as pd
from datetime import datetime

print df.ix[0:5]
                              date
file                              
gom3_197801.nc 2011-02-16 00:00:00
gom3_197802.nc 2011-02-16 00:00:00
gom3_197803.nc 2011-02-15 00:00:00
gom3_197804.nc 2011-02-17 00:00:00
gom3_197805.nc 2011-11-14 00:00:00

df['date'][0].toordinal()

Out[6]:
734184

df['date'].toordinal()

---------------------------------------------------------------------------
AttributeError                            Traceback (most recent call last)
<ipython-input-7-dbfd5e8b60f0> in <module>()
----> 1 df['date'].toordinal()

AttributeError: 'Series' object has no attribute 'toordinal'

I guess this is a basic question, but I've struggled reading docs for last 30 minutes.

How can I create an ordinal time column for my dataframe?

like image 679
Rich Signell Avatar asked Dec 13 '13 21:12

Rich Signell


3 Answers

Use apply:

df['date'].apply(lambda x: x.toordinal())
like image 173
lowtech Avatar answered Oct 27 '22 03:10

lowtech


you can also use map:

import datetime as dt
df['date'].map(dt.datetime.toordinal)
like image 22
behzad.nouri Avatar answered Oct 27 '22 03:10

behzad.nouri


For completeness:
Apply pd.Timestamp.toordinal

df['date'].apply(pd.Timestamp.toordinal)
like image 33
wwii Avatar answered Oct 27 '22 01:10

wwii