如何使用python将我的数据添加到json对象的开头

Question

我在json文件中使用了以下代码

"destinations": [
     {
        "/abc/def": {

  "proxy_pass":"https://{{application_destination}}/abc/service$is_args$args",
            "host": "{{application_destination}}",

            }
        }
]

我必须将proxy\u pass的url添加到某个变量中，然后将该变量添加到 使用python代码的代理传递

if "proxy_pass" in location_details:
            proxy_pass = location_details[proxy_pass]
            location_details["set"] = "$backend " + proxy_pass
            location_details["proxy_pass"] = "$backend"

但我得到的输出是在代理通过后，设置值正在打印 那么，如何使用python将set值添加到json对象的开头呢

Answer 1

Pythondict对象在Python 3.7之前是无序的

您可以使用^{}：

from collections import OrderedDict
import json


location_details = OrderedDict({
    "proxy_pass": "https://{{application_destination}}/abc/service$is_args$args",
    "host": "{{application_destination}}",
})

if "proxy_pass" in location_details:
    proxy_pass = location_details.pop('proxy_pass')
    location_details["set"] = "$backend " + proxy_pass
    location_details["proxy_pass"] = "$backend"

print(json.dumps(location_details, indent=4))

输出

{
    "host": "{{application_destination}}", 
    "set": "$backend https://{{application_destination}}/abc/service$is_args$args", 
    "proxy_pass": "$backend"
}

---

编辑

获得所需的订单

1. set
2. proxy_pass
3. host

可以使用^{}将host键移动到OrderedDict的末尾：

from collections import OrderedDict
import json


location_details = OrderedDict({
    "proxy_pass": "https://{{application_destination}}/abc/service$is_args$args",
    "host": "{{application_destination}}",
})

if "proxy_pass" in location_details:
    proxy_pass = location_details.pop('proxy_pass')
    location_details["set"] = "$backend " + proxy_pass
    location_details["proxy_pass"] = "$backend"
    location_details.move_to_end('host')

print(json.dumps(location_details, indent=4))

输出

{
    "set": "$backend https://{{application_destination}}/abc/service$is_args$args",
    "proxy_pass": "$backend",
    "host": "{{application_destination}}"
}

注意

也可以使用location_details.move_to_end(key, last=False)将key移动到字典的开头