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troubleshooting Question

How to create a Pandas DataFrame from another DataFrame's column, which is a list

Avatar of crompnk
crompnkFlag for United Kingdom of Great Britain and Northern Ireland asked on
PythonJSON* pandas* python3
5 Comments1 Solution967 ViewsLast Modified:
Hi, I have a python script that is creating a DataFrame from some json data.
I can create a DataFrame (df) from the data, but I need to create a DataFrame from the 'readings' column within the df DataFrame. My code is failing because the 'readings' column is a list.
Ultimately I need to create a DataFrame with the two DataFrames combined:

DataFrame needed
This is the python code I'm working with:

import pandas as pd
import json

data = {  
   'locationId':123546987,
   'parameters':[  
      {  
         'parameterId':'11',
         'unitId':'81',
         'customParameter':False,
         'readings':[  
            {  
               'timestamp':1538957700,
               'value':2306.078
            },
            {  
               'timestamp':1538959500,
               'value':2305.892
            },
            {  
               'timestamp':1538961300,
               'value':2305.981
            }
         ]
      },
      {  
         'parameterId':'1',
         'unitId':'1',
         'customParameter':False,
         'readings':[  
            {  
               'timestamp':1538957700,
               'value':25.575
            },
            {  
               'timestamp':1538959500,
               'value':25.572
            },
            {  
               'timestamp':1538961300,
               'value':25.575
            }
         ]
      }
   ]
}
         
val = json.loads(json.dumps(data))

val1 = val['parameters']

#val2 = [{'timestamp': 1538957700, 'value': 2306.078}, {'timestamp': 1538959500, 'value': 2305.892}, {'timestamp': 1538961300, 'value': 2305.981}]
val2 = val1['readings']

df = pd.DataFrame(val1).set_index('parameterId')
print(df)

df2 = pd.DataFrame(val2)
print(df2)

Thank you