datetime difference between dates

Question

I have a df like so:

  firstdate                seconddate
0 2011-01-01 13:00:00    2011-01-01 13:00:00
1 2011-01-02 14:00:00    2011-01-01 11:00:00
2 2011-01-02 16:00:00    2011-01-02 13:00:00
3 2011-01-04 12:00:00    2011-01-03 15:00:00
...

Seconddate is always before firstdate. I want to compute the difference between firstdate and seconddate in number of days and make this a column, if firstdate and seconddate are the same day, difference=0, if seconddate is the day before firstdate, difference=1 and so on until a week. How would I do this?

Whats the question here? how to find the diff between dates or how to delete based on the diff? — leoOrion, Oct 30 '20 at 04:00
Sorry should of been more clear. Diff between dates is most important, I realise it would be trivial to delete records > 7 now. — Scott Adamson, Oct 30 '20 at 04:02
https://stackoverflow.com/questions/33261397/pandas-calculate-time-difference-between-df-columns — Manvir, Oct 30 '20 at 04:09

score 1 · Accepted Answer · answered Oct 30 '20 at 04:06

1

df['first'] = pd.to_datetime(df['first'])
df['second'] = pd.to_datetime(df['second'])

df['diff'] = (df['first'] - df['second']).dt.days

This will add a column with the diff. You can delete based on it

df.drop(df[df.diff < 0].index)

# or

df = df[df.diff > 0]

answered Oct 30 '20 at 04:06

leoOrion

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Once you are done with deletion, you can drop the `diff` col also. – leoOrion Oct 30 '20 at 04:08

datetime difference between dates

1 Answers1