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json - ValueError: arrays must be all the same length - 将 JSON 解析为 Pandas DataFrame

问题描述

import requests
import json
import pandas as pd

data = requests.get("https://earthquake.usgs.gov/fdsnws/event/1/query?format=geojson")

json_data = data.json()

with open(r"C:\path\file.json",'w') as outfile:
    json.dump(json_data, outfile)

df = pd.read_json(r"C:\path\file.json")

当我尝试将 json 数据解析为 Pandas Dataframe 时，出现以下错误： ValueError: arrays must be all be same length

谁能帮我解决这个问题？

Traceback (most recent call last):
  File "c:/path/file.py", line 29, in <module>
    df = pd.read_json(r"C:\path\file.json")
  File "C:\ProgramData\Anaconda3\lib\site-packages\pandas\util\_decorators.py", line 199, in wrapper
    return func(*args, **kwargs)
  File "C:\ProgramData\Anaconda3\lib\site-packages\pandas\util\_decorators.py", line 296, in wrapper
    return func(*args, **kwargs)
  File "C:\ProgramData\Anaconda3\lib\site-packages\pandas\io\json\_json.py", line 618, in read_json
    result = json_reader.read()
  File "C:\ProgramData\Anaconda3\lib\site-packages\pandas\io\json\_json.py", line 755, in read
    obj = self._get_object_parser(self.data)
  File "C:\ProgramData\Anaconda3\lib\site-packages\pandas\io\json\_json.py", line 777, in _get_object_parser
    obj = FrameParser(json, **kwargs).parse()
  File "C:\ProgramData\Anaconda3\lib\site-packages\pandas\io\json\_json.py", line 886, in parse
    self._parse_no_numpy()
  File "C:\ProgramData\Anaconda3\lib\site-packages\pandas\io\json\_json.py", line 1118, in _parse_no_numpy
    self.obj = DataFrame(
  File "C:\ProgramData\Anaconda3\lib\site-packages\pandas\core\frame.py", line 468, in __init__
    mgr = init_dict(data, index, columns, dtype=dtype)
  File "C:\ProgramData\Anaconda3\lib\site-packages\pandas\core\internals\construction.py", line 283, in init_dict
    return arrays_to_mgr(arrays, data_names, index, columns, dtype=dtype)
  File "C:\ProgramData\Anaconda3\lib\site-packages\pandas\core\internals\construction.py", line 78, in arrays_to_mgr
    index = extract_index(arrays)
  File "C:\ProgramData\Anaconda3\lib\site-packages\pandas\core\internals\construction.py", line 397, in extract_index
    raise ValueError("arrays must all be same length")
ValueError: arrays must all be same length

标签： jsonpython-3.xpandasapidataframe

解决方案

更简单的方法是不保存到文件并使用json_normalize()

import requests
import json
import pandas as pd

data = requests.get("https://earthquake.usgs.gov/fdsnws/event/1/query?format=geojson")
json_data = data.json()

pd.json_normalize(json_data["features"])

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