Getting min and max Dates from a pandas dataframe

Question

How do I get the min and max Dates from a dataframe's major axis?

           value
Date                                           
2014-03-13  10000.000 
2014-03-21   2000.000 
2014-03-27   2000.000 
2014-03-17    200.000 
2014-03-17      5.000 
2014-03-17     70.000 
2014-03-21    200.000 
2014-03-27      5.000 
2014-03-27     25.000 
2014-03-31      0.020 
2014-03-31     12.000 
2014-03-31      0.022

Essentially I want a way to get the min and max dates, i.e. 2014-03-13 and 2014-03-31. I tried using numpy.min or df.min(axis=0), I'm able to get the min or max value but that's not what I want

score 134 · Accepted Answer · edited Aug 01 '18 at 03:17

134

'Date' is your index so you want to do,

print (df.index.min())
print (df.index.max())

2014-03-13 00:00:00
2014-03-31 00:00:00

edited Aug 01 '18 at 03:17

Merlin

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answered Apr 20 '14 at 03:43

Karl D.

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Pandas gets more intuitive the more you use it. – user2105469 Oct 27 '18 at 16:58
I thought I had set_index to the datetime field, but alas I forgot to reassign it! Should get these back in datetimes of course. – David Aug 01 '19 at 15:42
1

this assumes your df is indexed by date – Cybernetic Nov 11 '21 at 23:17

score 70 · Answer 2 · edited Jul 06 '20 at 08:47

70

min(df['some_property'])
max(df['some_property'])

The built-in functions work well with Pandas Dataframes.

edited Jul 06 '20 at 08:47

Stack Overflow User

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answered Apr 27 '17 at 11:32

J.Weed

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rachwa · Answer 3 · 2022-06-17T17:39:11.780

5

Use agg to determine the minimum and maximum value in one line:

In [5]: df['Date'].agg(['min', 'max'])
Out[5]: 
min    2014-03-13
max    2014-03-31

If your desired column is in the index, you have to reset the index first:

df.reset_index()['Date'].agg(['min', 'max'])

edited Jun 17 '22 at 17:39

answered May 09 '22 at 20:32

rachwa

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Getting min and max Dates from a pandas dataframe

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