python - Looping over groups in a grouped dataframe

Question

Consider this small example:

data={"X":[1, 2, 3, 4, 5], "Y":[6, 7, 8, 9, 10], "Z": [11, 12, 13, 14, 15])
frame=pd.DataFrame(data,columns=["X","Y","Z"],index=["A","A","A","B","B"])

I want to group frame with

grouped=frame.groupby(frame.index)

Then I want to loop over the groups by:

for group in grouped:

But I'm stuck on the next step: How can I extract the group in each loop as a pandas DataFrame so I can further process it?

Answer 1

df.groupby returns an iterable of 2-tuples: the index, and the group. You can iterate over each group like this:

for _, g in frame.groupby(frame.index):
    .... # do something with `g`

However, if you want to perform some operation on the groups, there are probably better ways than iteration.