如何在 pandas dataframe 中仅对正数进行分组连接总和

Question

I have dataframe like as show where I need create a new data frame by grouping the input dataframe by document number and concat all the descriptions(column name:Text)with space delimiter and sum up the positive amounts as a new column.

Input dataframe

   df
Doc Number    Text   Amount
122           DB1     25
122           DB2     25
122           DB3    -50
345           DB4     10
345           DB5     15
345           DB6     30
345           DB7    -55

Expectected Output

New dataframe (Df1)

Doc Number  Text           Amount
122        DB1 DB2 DB3     50
345        DB4 DB5 DB6 DB7 55

My code till now

df.groupby('Doc Number').apply(lambda x: ' '.join(x.Text))

How can this this be done?

Answer 1

Use pandas.DataFrame.groupby.agg :

new_df = df.groupby('Doc Number', as_index=False).agg({'Text': ' '.join, 'Amount': lambda x: sum(i for i in x if i > 0)})
print(new_df)

Output:

   Doc Number  Amount             Text
0         122      50      DB1 DB2 DB3
1         345      55  DB4 DB5 DB6 DB7