Pandas – how to reduce each row to a json column?

Let’s say we have the following df:

| col_a| col_b |
| -----| ----- |
| 1    | a     |
| 2    | b     |

And we want to reduce all rows to JSONs representing all columns row-wise:

|    json_representation        |
| ------------------------------| 
| {'col_a': 1, 'col_b': 'a'}    | 
| {'col_a': 2, 'col_b': 'b'}    |

Dicts are also good, since converting them to JSON strings is simple.

I am aiming for a solution where there is no need to know every column name, so answers here (up to the moment I am asking), are not the solution I am looking for.

How
Thanks.

>Solution :

here is one way to do it

use apply and convert the row using to_json

df.apply(lambda x: x.to_json( ), axis=1)

0    {"col_a":1,"col_b":"a"}
1    {"col_a":2,"col_b":"b"}
dtype: object

df['json']=df.apply(lambda x: x.to_json( ), axis=1)
df

col_a   col_b   json
0   1   a   {"col_a":1,"col_b":"a"}
1   2   b   {"col_a":2,"col_b":"b"}