pandas groupby sort descending order

Question

pandas groupby will by default sort. But I\'d like to change the sort order. How can I do this?

I\'m guessing that I can\'t apply a sort method to the returned gro

Answer 1

As of Pandas 0.18 one way to do this is to use the sort_index method of the grouped data.

Here's an example:

np.random.seed(1)
n=10
df = pd.DataFrame({'mygroups' : np.random.choice(['dogs','cats','cows','chickens'], size=n), 
                   'data' : np.random.randint(1000, size=n)})

grouped = df.groupby('mygroups', sort=False).sum()
grouped.sort_index(ascending=False)
print grouped

data
mygroups      
dogs      1831
chickens  1446
cats       933

As you can see, the groupby column is sorted descending now, indstead of the default which is ascending.