如何在 pandas dataframe 的列内创建列？

Question

Following is the code used to create a DataFrame.

import pandas as pd
cols = ['Col 1', 'Col 2', 'Col 3']
data = [['Row 1', '1.0', '{"tag1" : {0: \" \", 1: \" \"}, "tag2": {2: \" \", 3: \" \"}}'], ['Row 2', '2.0', '{"tag1" : {0: \" \", 1: \" \"}, "tag2": {2: \" \", 3: \" \"}}']]
df = pd.DataFrame(columns = cols, data = data)

Below is the output of the DataFrame df

   Col 1 Col 2                                                  Col 3
0  Row 1   1.0  {"tag1" : {0: " ", 1: " "}, "tag2": {2: " ", 3: " "}}
1  Row 2   2.0  {"tag1" : {0: " ", 1: " "}, "tag2": {2: " ", 3: " "}}

How can I convert the above DataFrame into any of the tabular format as shown below?

Answer 1

You can create each column using eval to convert the string into a dictionary and then accessing the required value, for example for the col 0 :

df[0] = df['Col 3'].apply(lambda x: eval(x)['tag1'][0])