python读取多个文件夹_Python：从文件夹中读取多个json文件

小编典典

一种选择是使用os.listdir列出目录中的所有文件，然后仅查找以’.json’结尾的文件：

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，您可以使用pandas DataFrame.from_dict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']

印刷品：

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

在这种情况下，我将一些json附加到列表中many_jsons。我列表中的第一个json实际上是一个geojson，其中包含蒙特利尔的一些地理数据。我已经很熟悉内容了，所以我打印出了“几何图形”，这让我对蒙特利尔感到满意。

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]

了解此代码对于在目录名称“ json”中有两个geojsons可能会有所帮助。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"}

2020-07-27