使用 Python 解析和打印 JSON 数据

Question

我是 JSON 新手，我正在使用 Python 从 JSON 数据中提取值。我正在使用另一个带有 cURL 的 shell 脚本获取 JSON 数据。

这是我从 shell 脚本（称为 test.sh）的 JSON 输出：

{"preview":true,"offset":0,"result":{"Country":"AU","count":"417"}}
{"preview":true,"offset":1,"result":{"Country":"BG","count":"7"}}
{"preview":true,"offset":2,"result":{"Country":"CA","count":"198"}}
{"preview":true,"offset":3,"result":{"Country":"CH","count":"1"}}
{"preview":true,"offset":4,"result":{"Country":"CN","count":"3"}}
{"preview":true,"offset":5,"result":{"Country":"CR","count":"1"}}
{"preview":true,"offset":6,"result":{"Country":"DE","count":"148"}}
{"preview":true,"offset":7,"result":{"Country":"DK","count":"1"}}
{"preview":true,"offset":8,"result":{"Country":"FI","count":"1"}}
{"preview":true,"offset":9,"result":{"Country":"FR","count":"1052"}}
{"preview":true,"offset":10,"result":{"Country":"GB","count":"1430"}}
{"preview":true,"offset":11,"result":{"Country":"HK","count":"243"}}
{"preview":false,"offset":12,"lastrow":true,"result":{"Country":"VG","count":"54"}}

我想将所有“Country”值和“count”值打印成这样的：

AU 417
BG 7
CA 198
...

为了做到这一点，我创建了一个循环来获取和打印所有需要的值，但是我得到了这个错误：

 AttributeError: 'str' object has no attribute 'read'

这是我的python代码：

import subprocess
import json
import sys
import subprocess
answer = subprocess.check_output(['./test.sh']) #test.sh contains the cURL command
json_obj = json.load(answer)
for i in json_obj['result']:
    print i['Country']
    print i['count']

我在这里错过了什么吗？

任何帮助将不胜感激， 非常感谢

Answer 1

我在帖子中看到了一些错误或误解的内容：

1. 如果您有一组 JSON 对象，则应将它们设为对象数组，或将它们一次解析为单独的文件或一个文件中的单独行（不推荐）。前者会更容易、更可靠：

   [{"obj":1},{"obj":2},...]
   

2. 如果您直接从字符串而不是文件加载，则应使用 json.loads 而不是 json.load。

3. 这是一个工作示例：

   import json
   
   answers = '[{"preview":true,"offset":0,"result":{"Country":"AU","count":"417"}}' + \
             ',{"preview":true,"offset":1,"result":{"Country":"BG","count":"7"}}]'
   json_obj = json.loads(answers)
   
   for i in json_obj:
       print i['result']['Country'], i['result']['count']
   

Answer 2

您的数据是多个 json 对象。

您可能希望将其用大括号括起来（{ 和 }），并将其视为所有对象的唯一集合。

{
{"preview":true,"offset":0,"result":{"Country":"AU","count":"417"}}
{"preview":true,"offset":1,"result":{"Country":"BG","count":"7"}}
{"preview":true,"offset":2,"result":{"Country":"CA","count":"198"}}
{"preview":true,"offset":3,"result":{"Country":"CH","count":"1"}}
{"preview":true,"offset":4,"result":{"Country":"CN","count":"3"}}
{"preview":true,"offset":5,"result":{"Country":"CR","count":"1"}}
{"preview":true,"offset":6,"result":{"Country":"DE","count":"148"}}
{"preview":true,"offset":7,"result":{"Country":"DK","count":"1"}}
{"preview":true,"offset":8,"result":{"Country":"FI","count":"1"}}
{"preview":true,"offset":9,"result":{"Country":"FR","count":"1052"}}
{"preview":true,"offset":10,"result":{"Country":"GB","count":"1430"}}
{"preview":true,"offset":11,"result":{"Country":"HK","count":"243"}}
{"preview":false,"offset":12,"lastrow":true,"result":{"Country":"VG","count":"54"}}
}

Answer 3

对于结果输出

{"preview":true,"offset":0,"result":{"Country":"AU","count":"417"}}
{"preview":true,"offset":1,"result":{"Country":"BG","count":"7"}}
{"preview":true,"offset":2,"result":{"Country":"CA","count":"198"}}
{"preview":true,"offset":3,"result":{"Country":"CH","count":"1"}}
{"preview":true,"offset":4,"result":{"Country":"CN","count":"3"}}
{"preview":true,"offset":5,"result":{"Country":"CR","count":"1"}}

实际上有几行 doc（单个 json）。 您应该逐行阅读它们，而不是逐行阅读。

这是建议。您可以暂时保存 JSON 文档，然后阅读并加载它们。

1. 保存test.sh > tmp.txt
2. 逐行阅读

with open('tmp.txt', 'r') as f: for i in f: doc = f.readline() try: the_dict = json.loads(doc) print(the_dict['Country']) except Exception, e: print(str(e)) 或者如果你坚持使用子进程，你仍然可以逐行读取文件。只要记住你得到的输出是一个列表。您应该使用循环来迭代所有内容。

Answer 4

简单的解决方案是， 让我们从你的答案开始：

answer = '''{"preview":true,"offset":0,"result":{"Country":"AU","count":"417"}}
{"preview":true,"offset":1,"result":{"Country":"BG","count":"7"}}
{"preview":true,"offset":2,"result":{"Country":"CA","count":"198"}}
{"preview":true,"offset":3,"result":{"Country":"CH","count":"1"}}
{"preview":true,"offset":4,"result":{"Country":"CN","count":"3"}}
{"preview":true,"offset":5,"result":{"Country":"CR","count":"1"}}
{"preview":true,"offset":6,"result":{"Country":"DE","count":"148"}}
{"preview":true,"offset":7,"result":{"Country":"DK","count":"1"}}
{"preview":true,"offset":8,"result":{"Country":"FI","count":"1"}}
{"preview":true,"offset":9,"result":{"Country":"FR","count":"1052"}}
{"preview":true,"offset":10,"result":{"Country":"GB","count":"1430"}}
{"preview":true,"offset":11,"result":{"Country":"HK","count":"243"}}
{"preview":false,"offset":12,"lastrow":true,"result":{"Country":"VG","count":"54"}}'''

将其转换为有效的 json

import json
answer = json.loads('['+answer.replace('\n',',')+']')

打印你的结果：

for i in answer:
    print i['result']['Country'],i['result']['count']

AU 417
BG 7
CA 198
CH 1
CN 3
CR 1
DE 148
DK 1
FI 1
FR 1052
GB 1430
HK 243
VG 54

所以你的完整代码是：

import subprocess
import json
answer = subprocess.check_output(['./test.sh'])
answer = json.loads('['+answer.replace('\n',',')+']')
for i in answer:
    print i['result']['Country'],i['result']['count']

Answer 5

请将代码存入test.py，数据存入test.json。

test.py

import json


with open('/tmp/test.json') as f:
    for i in f:
        data = json.loads(i)
        print("{Country} {count}".format(**data["result"]))

test.json

$ python test.py
AU 417
BG 7
CA 198
CH 1
CN 3
CR 1
DE 148
DK 1
FI 1
FR 1052
GB 1430
HK 243
VG 54

---

你也可以在你的 prog 中试一试：

for i in answer:
    data = json.loads(i)
    print("{Country} {count}".format(**data["result"]))