Question

我正在将python的输出写入json文件。

我尝试过的是：

with open(r"c:\csv\file.json", "w") as f:
    ec2 = boto3.resource('ec2')
    #ids = inst_id
    for instance in ec2.instances.filter(InstanceIds=[inst_id]):
       #print (instance.tags)
       for tag in instance.tags:
           val1 = (tag['Value'])
           val2 = (tag['Key'])
           json.dump([{"Key": val2, "Value": val1}], f, indent=4, separators=(',', ': '))

预期输出：

[
  {
    "Key": "Name",
    "Value": "node1"
  },
  {
    "Key": "owner",
    "Value": "jhonson"
  },
  {
    "Key": "managed",
    "Value": "yes"
  }
]

我得到的是Invalid Output: , missing after each key，每对都会有额外的[]：

[
    {
        "Key": "Name",
        "Value": "node1"
    }
][
    {
        "Key": "owner",
        "Value": "jhonson"
    }
][
    {
        "Key": "managed",
        "Value": "yes"
    }
]

如果我通常只在下面的控制台中打印变量，则输出：

Name,node1
owner,jhonson
managed,yes

有人可以建议我的dump语法有什么问题吗？

Answer 1

编辑：

将您自己的字典附加到列表然后将整个内容转储到JSON可能会更容易：

for instance in ec2.instances.filter(InstanceIds=[inst_id]):
    keys = []
    for tag in instance.tags:       
        val1 = tag['Value']
        val2 = tag['Key']
        keys.append({val1: val2})

with open("data_file.json", "w") as write_file:
    json.dump(data, write_file, indent=4)

Answer 2

这是因为import numpy as np import cv2 cap = cv2.VideoCapture(0) while(True): # Capture frame-by-frame ret, frame = cap.read() # Our operations on the frame come here gray = cv2.cvtColor(frame, cv2.COLOR_BGR2GRAY) # Display the resulting frame cv2.imshow('frame',gray) if cv2.waitKey(1) & 0xFF == ord('q'): break # When everything done, release the capture cap.release() cv2.destroyAllWindows()第一个参数json.dump()是您希望序列化为JSON格式的文件的对象（类似于f）。您正在for循环中传递obj。因此，不是创建包含多个对象的单个JSON数组，而是创建包含单个对象的多个JSON数组。 [{"Key": val2, "Value": val1}]应该发生在for循环之外，并被赋予构造好的对象列表。

尝试一下：

json.dump()

json文件写入格式出现问题

2 个答案: