How to group dataframe rows into series in pandas groupby

Question

I am trying to group by data into series. A similar question can be found on stackoverflow here but it groupby data into a list and I want into series. Any idea.

For list, the solution is like this

df1 = pd.DataFrame( {'a':['A','A','B','B','B','C'], 'b':[1,2,5,5,4,6],'c':[1,2,5,5,4,6]})

df1.groupby('a').agg(list)

I tried something like this

df1.groupby(a).agg(lambda x: pd.Series(list(x)))

But its not working So I tried this

for i in df1.columns:
  df1[i]=df1[i].apply(lambda x:np.array(x))

But I want to convert to sereis

I want output like this

      b      c 
A   1 2     1 2
B   5 5 4   5 5 4
C   6       6

score 0 · Answer 1 · answered Dec 26 '20 at 03:25

0

Try:

df1.astype(str).groupby('a')['b'].agg(','.join).to_frame()

Output:

answered Dec 26 '20 at 03:25

Scott Boston

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if i have more than 1 column, I got this error. `AttributeError: 'DataFrame' object has no attribute 'to_frame'` – Talha Anwar Dec 26 '20 at 19:41
Remove the to_ framr with more than one column you don't need it. – Scott Boston Dec 27 '20 at 17:12
but it will be str type instead of series type – Talha Anwar Dec 27 '20 at 17:28
You want a list or comma separated string? – Scott Boston Dec 27 '20 at 17:39
i want pandas series – Talha Anwar Dec 27 '20 at 17:44

How to group dataframe rows into series in pandas groupby

1 Answers1