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pandasdataframenestedpandas-explode

Parsing or exploding a list of dictionaries in a dataframe


I have a dataframe with lists of nested dictionaries that want to unpack.

I need to get the date and price from the priceHistory and the items listed in both WaterConservation and EnergyEfficient. The sample below is only two rows of a much larger dataframe where there are not the same number of dictionary items per dataframe row.

df = pd.DataFrame(
    [[19, [{'priceChangeRate': 0, 'date': '2015-05-29', 'source': 'Public Record', 'postingIsRental': False, 'time': 1432857600000, 'sellerAgent': None, 'showCountyLink': False, 'attributeSource': {'infoString2': 'Public Record', 'infoString3': None, 'infoString1': None}, 'pricePerSquareFoot': 275, 'buyerAgent': None, 'event': 'Sold', 'price': 877205}], ['Low flow commode', 'Low flow fixtures', 'Water-Smart Landscaping'],''],
     [89, [{'priceChangeRate': 0.090909090909091, 'date': '2023-07-14', 'source': 'Public Record', 'postingIsRental': False, 'time': 1689292800000, 'sellerAgent': {'name': 'seller1', 'photo': {'url': 'https://sellerphoto1.jpg'}, 'profileUrl': '/profile/sellerprofile1/'}, 'showCountyLink': False, 'attributeSource': {'infoString2': 'Public Record', 'infoString3': None, 'infoString1': None}, 'pricePerSquareFoot': 308, 'buyerAgent': {'name': 'buyer1', 'photo': {'url': 'https://buyerphoto1.jpg'}, 'profileUrl': '/profile/buyerprofile1/'}, 'event': 'Sold', 'price': 1200000}, {'priceChangeRate': 0, 'date': '2015-08-20', 'source': 'Public Record', 'postingIsRental': False, 'time': 1440028800000, 'sellerAgent': None, 'showCountyLink': False, 'attributeSource': {'infoString2': 'Public Record', 'infoString3': None, 'infoString1': None}, 'pricePerSquareFoot': 50, 'buyerAgent': None, 'event': 'Sold', 'price': 195000}],'', ['Windows', 'Insulation', 'HVAC', 'Appliances', 'Lighting']]],
    columns=['id', 'priceHistory', 'WaterConservation', 'EnergyEfficient'])

I have tried too many things to list here, but this seems to be the most efficient (just to get priceHistory) (source):

df = pd.concat(
    [
        df,
        df.pop("priceHistory").apply(
            lambda x: pd.Series({k: v for d in x for k, v in d.items()})
        ),
    ],
    axis=1,
)
print(df)

But I get this error: TypeError: 'float' object is not iterable


Solution

  • You can use Series.explode with json_normalize, creste same index by DataFrame.set_index, so possible use DataFrame.join:

    s = df.pop('priceHistory').explode()
    out = df.join(pd.json_normalize(s).set_index(s.index))
    

    print (out)
       id                                  WaterConservation  \
    0  19  [Low flow commode, Low flow fixtures, Water-Sm...   
    1  89                                                      
    1  89                                                      
    
                                         EnergyEfficient  priceChangeRate  \
    0                                                            0.000000   
    1  [Windows, Insulation, HVAC, Appliances, Lighting]         0.090909   
    1  [Windows, Insulation, HVAC, Appliances, Lighting]         0.000000   
    
             date         source  postingIsRental           time  sellerAgent  \
    0  2015-05-29  Public Record            False  1432857600000          NaN   
    1  2023-07-14  Public Record            False  1689292800000          NaN   
    1  2015-08-20  Public Record            False  1440028800000          NaN   
    
       showCountyLink  pricePerSquareFoot  buyerAgent event    price  \
    0           False                 275         NaN  Sold   877205   
    1           False                 308         NaN  Sold  1200000   
    1           False                  50         NaN  Sold   195000   
    
      attributeSource.infoString2 attributeSource.infoString3  \
    0               Public Record                        None   
    1               Public Record                        None   
    1               Public Record                        None   
    
      attributeSource.infoString1 sellerAgent.name     sellerAgent.photo.url  \
    0                        None              NaN                       NaN   
    1                        None          seller1  https://sellerphoto1.jpg   
    1                        None              NaN                       NaN   
    
         sellerAgent.profileUrl buyerAgent.name     buyerAgent.photo.url  \
    0                       NaN             NaN                      NaN   
    1  /profile/sellerprofile1/          buyer1  https://buyerphoto1.jpg   
    1                       NaN             NaN                      NaN   
    
         buyerAgent.profileUrl  
    0                      NaN  
    1  /profile/buyerprofile1/  
    1                      NaN