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当我在 Ubuntu 16.04 上运行 python 脚本时出现以下错误。

当我运行相同的代码但不确定哪个软件包未正确安装时，它在 Windows 上运行良好。

import subprocess
import json

#one vnet and one subnet in the resourcegroup.
def get_vnet_name(resourcegroup):
    get_vnet_command=["az","network","vnet","list","--resource-group",resourcegroup]
    get_vnet=subprocess.run(get_vnet_command, shell = True, stdout=subprocess.PIPE, stderr = subprocess.PIPE)
    a=get_vnet.stdout.decode('utf-8')
    d=json.loads(a)
    for item in d:
        vname=item["name"]
        subnets=item["subnets"]
    for i in subnets:
        subnetname=i["name"]
    return vname,subnetname

def create_vm(vm_resourcegroup,vm_name, vm_image,vm_username, vm_passowrd,vm_vnet,vm_subnet, vm_size):
    create_vm_command=["az","vm","create","--resource-group",vm_resourcegroup,"--name",vm_name,"--image",vm_image, "--admin-username", vm_username,"--admin-password",vm_passowrd,"--vnet-name",vm_vnet,"--subnet",vm_subnet,"--size", vm_size]
    create_vm=subprocess.run(create_vm_command, shell = True, stdout=subprocess.PIPE, stderr = subprocess.PIPE)
    return


if __name__=="__main__":
    rscgroup_name="vm-test-group"
    avm_name="testvm1"
    avm_image="Win2019Datacenter"
    avm_username="myuser"
    avm_password="mypassword"
    avm_size="Standard_D2_V3"
    vault_name = "aqrahkeyvault"
    certificate_name = "staticwebsite"

    avm_vnet,avm_subnet=get_vnet_name(rscgroup_name)
    create_vm(rscgroup_name,avm_name,avm_image,avm_username,avm_password,avm_vnet,avm_subnet,avm_size)

下面是我得到的与 json.decoder 相关的错误：

  root@linuxvm:/home/azureuser# python3.6  test2.py
    Traceback (most recent call last):
      File "test2.py", line 32, in <module>
        avm_vnet,avm_subnet=get_vnet_name(rscgroup_name)
      File "test2.py", line 9, in get_vnet_name
        d=json.loads(a)
      File "/usr/lib/python3.6/json/__init__.py", line 354, in loads
        return _default_decoder.decode(s)
      File "/usr/lib/python3.6/json/decoder.py", line 339, in decode
        obj, end = self.raw_decode(s, idx=_w(s, 0).end())
      File "/usr/lib/python3.6/json/decoder.py", line 357, in raw_decode
        raise JSONDecodeError("Expecting value", s, err.value) from None
    json.decoder.JSONDecodeError: Expecting value: line 2 column 6 (char 6)

我尝试安装 python 并没有解决问题。

4

1 回答 1

2

我试图重现您的问题并成功找出原因。实际上，您的脚本基本上是正确的，但您可能不会考虑az命令不返回任何结果的情况stdout。

例如，我的订阅中有一个不存在的资源组，例如non-exist-rg. 如果我将它作为参数的值传递，--resource-group下面的脚本将返回错误信息stderr，stdout值为b''.

import subprocess
resourcegroup = 'non-exist-rg'
get_vnet_command=["az","network","vnet","list","--resource-group",resourcegroup]
get_vnet=subprocess.run(get_vnet_command, shell = True, stdout=subprocess.PIPE, stderr = subprocess.PIPE)

stdout&的结果stderr如下。

>>> get_vnet.stdout
b''
>>> get_vnet.stderr
b"ERROR: Resource group 'non-exist-rg' could not be found.\r\n"

因此，如果您将stdout值传递给json.loads函数，它将引发与您相同的问题json.decoder.JSONDecodeError: Expecting value: line 1 column 1 (char 0)，因为json.loads无法处理空内容。在这里，取值的decode函数或函数不是必须的，可以接收如下图的值。bytesstdoutstderrjson.loadsbytes

在此处输入图像描述

所以要修复它，解决方案是检查stdout值是否为空或stderr值是否为非空。

def get_vnet_name(resourcegroup):
    get_vnet_command=["az","network","vnet","list","--resource-group",resourcegroup]
    get_vnet=subprocess.run(get_vnet_command, shell = True, stdout=subprocess.PIPE, stderr = subprocess.PIPE)
    # decode for stdout is not necessary
    # a=get_vnet.stdout.decode('utf-8')
    vname,subnetname = '', ''
    if get_vnet.stdout == b'':
        d=json.loads(get_vnet.stdout)
        for item in d:
            vname=item["name"]
            subnets=item["subnets"]
        for i in subnets:
            subnetname=i["name"]
    return vname,subnetname

然后，您需要在调用方法之前检查vname&值。subnetnamecreate_vm

希望能帮助到你。

于 2019-06-17T08:19:12.173 回答