Python and Pandas - Sorting data by datetime is not in ascending order

Question

I am trying to sort some data using Python/Pandas by year and month for a line plot.

My code is:

df.groupby(df['EXTRACT_DATE'].dt.strftime('%Y-%m'))['data'].sum().sort_values(ascending=True)

Which is returning:

Which is clearly not in order, but I'm not sure why and my data is like this:

BENY · Accepted Answer · 2019-04-04 14:48:58Z

3

Change to sort_index, after groupby your EXTRACT_DATE became index , so when you do sort_values , it sort the data not the %Y-%m

df.groupby(df['EXTRACT_DATE'].dt.strftime('%Y-%m'))['data'].sum().sort_index()

answered Apr 4, 2019 at 14:48

BENY

324k22 gold badges176 silver badges250 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

Andrew F · Accepted Answer · 2019-04-04 14:49:09Z

1

You're using .sort_values() which sorts by the value (the sum in this case) and not by the index (the date). What you want to use instead is .sort_index().

answered Apr 4, 2019 at 14:49

Andrew F

2,9701 gold badge17 silver badges25 bronze badges

1 Comment

Maverick Over a year ago

Yes of course, thank you! Wood for the trees with this one!

Collectives™ on Stack Overflow

Python and Pandas - Sorting data by datetime is not in ascending order

2 Answers 2

Comments

1 Comment

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

Comments

1 Comment

Your Answer

Sign up or log in

Post as a guest

Related