連続したjsonをpandasのDataFrameに変換したい

Question

連続したjsonをpandasのDataFrameに変換したい

{"name":"Tom","age":"29","Type":"A","ADRESS":["W","E"], "MAJOR": ["A", "B", "C", "D", "E"]}}
{"name":"Juddy","age":"25","Type":"B","ADRESS":"Q", "MAJOR": ["A", "B", "C", "D", "E"]}}
{"name":"John","age":"9","Type":"O","ADRESS":["M","P","C"], "MAJOR": ["A", "B", "C", "D", "E"]}}

というjsonがあります。この連続したjsonをpandasのDataFrameに変換したいです。

import pandas as pd
import numpy as np
import json

decoder = json.JSONDecoder()
f = open('data.json', 'r')
for line in f.readlines():
    data = decoder.decode(line)
　  df = pd.DataFrame(data)

とコードを書いて実行すると、
ValueError: arrays must all be same length
とエラーが出ました。Tracebackには

---------------------------------------------------------------------------
ValueError                                Traceback (most recent call last)
<ipython-input-8-bfb39aca863a> in <module>()
      3 for line in f.readlines():
      4     data = decoder.decode(line)
----> 5     df = pd.DataFrame(data)

~/anaconda3/lib/python3.6/site-packages/pandas/core/frame.py in __init__(self, data, index, columns, dtype, copy)
    328                                  dtype=dtype, copy=copy)
    329         elif isinstance(data, dict):
--> 330             mgr = self._init_dict(data, index, columns, dtype=dtype)
    331         elif isinstance(data, ma.MaskedArray):
    332             import numpy.ma.mrecords as mrecords

~/anaconda3/lib/python3.6/site-packages/pandas/core/frame.py in _init_dict(self, data, index, columns, dtype)
    459             arrays = [data[k] for k in keys]
    460 
--> 461         return _arrays_to_mgr(arrays, data_names, index, columns, dtype=dtype)
    462 
    463     def _init_ndarray(self, values, index, columns, dtype=None, copy=False):

~/anaconda3/lib/python3.6/site-packages/pandas/core/frame.py in _arrays_to_mgr(arrays, arr_names, index, columns, dtype)
   6161     # figure out the index, if necessary
   6162     if index is None:
-> 6163         index = extract_index(arrays)
   6164     else:
   6165         index = _ensure_index(index)

~/anaconda3/lib/python3.6/site-packages/pandas/core/frame.py in extract_index(data)
   6209             lengths = list(set(raw_lengths))
   6210             if len(lengths) > 1:
-> 6211                 raise ValueError('arrays must all be same length')
   6212 
   6213             if have_dicts:

と出ました。

　　name    age    Type
0     Tom      29       A
1      Juddy   25       B
2     John      9        O

という形のDataFrameを作りたいです。何が問題でどうコードを修正すればいいでしょうか？

Answer 1

以下のようにpandas.read_jsonにうまく適合させたjson文字列を作りこんでやれば一発でできます。

with open('data.json','r') as f:
    js = '[' + ','.join(f) + ']'
    print(js)

import pandas as pd
df = pd.read_json(js,orient='records')
print(df)

なお、data.jsonは

{"name":"Tom","age":"29","Type":"A","ADRESS":["W","E"]}
{"name":"Juddy","age":"25","Type":"B","ADRESS":"Q"}
{"name":"John","age":"9","Type":"O","ADRESS":["M","P","C"]}

や

{"name":"Tom",  "age":"29","Type":"A","ADRESS":["W","E"],     "MAJOR": ["A", "B", "C", "D", "E"]}
{"name":"Juddy","age":"25","Type":"B","ADRESS":["Q"],         "MAJOR": ["A", "B", "C", "D", "E"]}
{"name":"John",  "age":"9","Type":"O","ADRESS":["M","P","C"], "MAJOR": ["A", "B", "C", "D", "E"]}

のような内容を想定しています。

Comments

[kaitotokai]

ありがとうございます。print(df)で出力された結果は、テーブル形式ではないのですが、これでpandasのDataFrameに変換できるという認識で合っていますか？

[can110]

df がどんなものであるかは、print(type(df)) や print(df.info()) で確認できます。