How to add a column to a dataframe pandas so its value is dict?-CodePudding

I have a directory with the following structure:

value_students_shop = {'hypermarket': 0.143,
                       'supermarket': 0.125, 
                       'small_shop': 0.15}

And, for example, the following data set:

df
col1   col2
1      1
2      2
3      3
4      4

I need to create a new column in the dataframe so that its values are a dict, that is, I need the following result:

df
col1   col2   col3
1      1      {'hypermarket': 0.143, 'supermarket': 0.125, 'small_shop': 0.15}
2      2      {'hypermarket': 0.143, 'supermarket': 0.125, 'small_shop': 0.15}
3      3      {'hypermarket': 0.143, 'supermarket': 0.125, 'small_shop': 0.15}
4      4      {'hypermarket': 0.143, 'supermarket': 0.125, 'small_shop': 0.15}

How can I do that?

CodePudding user response：

here is one way about it

df['col3'] = str(value_students_shop)
df

    col1    col2    col3
0   1   1   {'hypermarket': 0.143, 'supermarket': 0.125, '...
1   2   2   {'hypermarket': 0.143, 'supermarket': 0.125, '...
2   3   3   {'hypermarket': 0.143, 'supermarket': 0.125, '...
3   4   4   {'hypermarket': 0.143, 'supermarket': 0.125, '...

you can access values in dictionary as follows, using literal_eval
df['col3'].apply(literal_eval)[0]['hypermarket']
>>> 0.143

alternate solution

# wrap the dictionary in a list, it get stores as a dictionary
df['col3']=[value_students_shop]*len(df)
df

    col1    col2    col3
0   1   1   {'hypermarket': 0.143, 'supermarket': 0.125, '...
1   2   2   {'hypermarket': 0.143, 'supermarket': 0.125, '...
2   3   3   {'hypermarket': 0.143, 'supermarket': 0.125, '...
3   4   4   {'hypermarket': 0.143, 'supermarket': 0.125, '...

when wrapping in a list, you can access dictionary values as follows

df['col3'][0]['hypermarket']
>>> 0.143

CodePudding user response：

please try this you can use str() instead of json.dumps. but when you revert it to dictionary using json.loads(), it is better to use json.dumps


import json
df['col3'] = json.dumps(value_students_shop)