Question

我无法遍历JSON文件以获取键的所有值。我尝试了多种写此错误的方法。

# Import package
from urllib.request import urlretrieve

# Import pandas
import pandas as pd

# Assign url of file: url
url = 'https://data.sfgov.org/resource/wwmu-gmzc.json'

# Save file locally
urlretrieve(url, 'wwmu-gmzc.json')


# Loading JSONs in Python
import json
with open('wwmu-gmzc.json', 'r') as json_file:
    #json_data = json.load(json_file) # type list
    json_data = json.load(json_file)[0] # turn into type dict

print(type(json_data))

# Print each key-value pair in json_data
#for k in json_data.keys():
#    print(k + ': ', json_data[k])
for line in json_data['title']:
    print(line)
#w_title = json_data['title']
#print(w_title)
for key, value in json_data.items():
    print(key + ':', value)
    #print(json_data.keys('title') + ':' , jason_data['title'])

此代码的当前版本仅给出文件的第一行：

<class 'dict'> 1 8 0 release_year: 2011 actor_2: Nithya Menon writer: Umarji Anuradha, Jayendra, Aarthi Sriram, & Suba  locations: Epic Roasthouse (399 Embarcadero) director: Jayendra title: 180 production_company: SPI Cinemas actor_1: Siddarth actor_3: Priya Anand

以下已更正的代码，并说明了缺少的密钥：

# Loading JSONs in Python
import json
with open('wwmu-gmzc.json', 'r') as json_file:
    content = json_file.read()
    json_data = json.loads(content)

print(type(json_data))

for json_i in json_data:
    try:
        print(json_i['locations'])
    except:
        print('***** NO KEY FOUND *****')

Answer 1

您仅在数据集中加载第一个数据。

with open('wwmu-gmzc.json', 'r') as json_file:
    json_data = json.load(json_file) # Input is list of dict. So,load everything

for json_i in json_data:
    print(json_i.get('your_key', 'default_value'))

Answer 2

您的代码不起作用，因为您正在获取的数据实际上是一个列表。要读取列表中的每个项目（每个项目都是键值对），您可以这样做。

# Import package
from urllib.request import urlretrieve
import json

# Assign url of file: url
url = 'https://data.sfgov.org/resource/wwmu-gmzc.json'

# Save file locally
urlretrieve(url, 'wwmu-gmzc.json')


# Loading JSONs in Python
with open('wwmu-gmzc.json', 'r') as json_file:
    content = json_file.read()
    json_data = json.loads(content)


for item in json_data:
    print('======')
    for key, value in item.items():
        print(key + ':', value)

获取json列表文件python中键的所有值

2 个答案: