CODEWITHSUNDEEP
pythonpandaspandas-groupby
Dmitry Bubnenkov
Dmitry Bubnenkov

Reputation: 9859

Why groupby in Pandas print not all columns?

q = [{"name":"Mike","age":21, "text": "aaa"},{"name":"Jow","age":22, "text": "bbb"},{"name":"Piter","age":22, "text": "ccc"},{"name":"David","age":25, "text": "ddd"}]
df = pd.DataFrame(q)
result = df["name"].groupby(df['age']).agg(','.join).to_frame()

print(df)
print('---')
print(result)

Output:

$ app.py
   age   name text
0   21   Mike  aaa
1   22    Jow  bbb
2   22  Piter  ccc
3   25  David  ddd
---
          name
age
21        Mike
22   Jow,Piter
25       David

But where is my text column? How to add it in result output?

Upvotes: 1

Views: 670

Answers (2)

jezrael
jezrael

Reputation: 862441

Your code working with Name column, so text column is omitted:

#group column name by column age
result = df["name"].groupby(df['age']).agg(','.join).to_frame()

#more common altearnative - group by column age columns specified in [] after groupby()
result = df.groupby('age')['name'].agg(','.join).to_frame()
print (result)
          name
age           
21        Mike
22   Jow,Piter
25       David

result = df.groupby('age')['text'].agg(','.join).to_frame()
print (result)
        text
age         
21       aaa
22   bbb,ccc
25       ddd

#if need specified multiple columns
result = df.groupby('age')['name','text'].agg(','.join)
print (result)
          name     text
age                    
21        Mike      aaa
22   Jow,Piter  bbb,ccc
25       David      ddd

#if omit [] proceses all non numeric columns
result = df.groupby('age').agg(','.join)
print (result)
          name     text
age                    
21        Mike      aaa
22   Jow,Piter  bbb,ccc
25       David      ddd

Upvotes: 1

Arthur Gouveia
Arthur Gouveia

Reputation: 744

When you do df["name"] you are slicing only the "name" column, so all other columns will "disappear".

I guess that you're trying to do the following:

result = df.groupby('age').agg(','.join)

print(df)
print('---')
print(result)

   age   name text
0   21   Mike  aaa
1   22    Jow  bbb
2   22  Piter  ccc
3   25  David  ddd
---
          name     text
age                    
21        Mike      aaa
22   Jow,Piter  bbb,ccc
25       David      ddd

Upvotes: 2

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