Python：从文件夹中读取多个json文件

我想知道如何阅读几本json来自单个文件夹的文件（不指定文件名，只是它们是 json 文件）。

此外，还可以将它们变成pandas数据框？

你能给我一个基本的例子吗？

一种选择是列出目录中的所有文件操作系统列表目录 https://docs.python.org/2/library/os.html#os.listdir然后只查找以 '.json' 结尾的内容：

import os, json
import pandas as pd

path_to_json = 'somedir/'
json_files = [pos_json for pos_json in os.listdir(path_to_json) if pos_json.endswith('.json')]
print(json_files)  # for me this prints ['foo.json']

现在你可以使用pandas了DataFrame.from_dict http://pandas.pydata.org/pandas-docs/dev/generated/pandas.DataFrame.from_dict.html将 json（此时为 python 字典）读入 pandas 数据帧：

montreal_json = pd.DataFrame.from_dict(many_jsons[0])
print montreal_json['features'][0]['geometry']

Prints:

{u'type': u'Point', u'coordinates': [-73.6051013, 45.5115944]}

在本例中，我已将一些 json 附加到列表中many_jsons。我列表中的第一个 json 实际上是geojson http://geojson.org/以及蒙特利尔的一些地理数据。我已经熟悉了内容，所以我打印了“几何图形”，它给了我蒙特利尔的经度/纬度。

以下代码总结了以上所有内容：

import os, json
import pandas as pd

# this finds our json files
path_to_json = 'json/'
json_files = [pos_json for pos_json in os.listdir(path_to_json) if pos_json.endswith('.json')]

# here I define my pandas Dataframe with the columns I want to get from the json
jsons_data = pd.DataFrame(columns=['country', 'city', 'long/lat'])

# we need both the json and an index number so use enumerate()
for index, js in enumerate(json_files):
    with open(os.path.join(path_to_json, js)) as json_file:
        json_text = json.load(json_file)

        # here you need to know the layout of your json and each json has to have
        # the same structure (obviously not the structure I have here)
        country = json_text['features'][0]['properties']['country']
        city = json_text['features'][0]['properties']['name']
        lonlat = json_text['features'][0]['geometry']['coordinates']
        # here I push a list of data into a pandas DataFrame at row given by 'index'
        jsons_data.loc[index] = [country, city, lonlat]

# now that we have the pertinent json data in our DataFrame let's look at it
print(jsons_data)

对我来说这打印：

  country           city                   long/lat
0  Canada  Montreal city  [-73.6051013, 45.5115944]
1  Canada        Toronto  [-79.3849008, 43.6529206]

了解此代码可能会有所帮助，我在目录名称“json”中有两个 geojson。每个 json 具有以下结构：

{"features":
[{"properties":
{"osm_key":"boundary","extent":
[-73.9729016,45.7047897,-73.4734865,45.4100756],
"name":"Montreal city","state":"Quebec","osm_id":1634158,
"osm_type":"R","osm_value":"administrative","country":"Canada"},
"type":"Feature","geometry":
{"type":"Point","coordinates":
[-73.6051013,45.5115944]}}],
"type":"FeatureCollection"}