生成 JSON 输出而不是 key=value CSV

Question

Python 版本 2.7.10

我有这个脚本（它抓取 AWS EBS 卷元数据），它当前生成一个 key=value 对数据，它是每行输出的 CSV（逗号分隔值）。

Python 脚本：

#!/usr/bin/python

#Do `sudo pip install boto3` first
import boto3
import json

def generate(key, value):
    """
    Creates a nicely formatted Key(Value) item for output
    """
    return '{}={}'.format(key, value)
    #if isinstance(value,int):
    #    return '\"{}\": {}'.format(key, value)
    #else:
    #    return '\"{}\": \"{}\"'.format(key, value)

def main():
    ec2 = boto3.resource('ec2', region_name="us-west-2")
    volumes = ec2.volumes.all()

    for vol in volumes:
        if vol.state == "available":
            vol_state_num_value = 1
        else:
            vol_state_num_value = 0
        if vol.snapshot_id == "":
            vol_snapshot_id = "None"
        else:
            vol_snapshot_id = vol.snapshot_id

        output_parts = [
            # Volume level details
            generate('vol_id', vol.volume_id),
            generate('az', vol.availability_zone),
            generate('vol_type', vol.volume_type),
            generate('size', vol.size),
            generate('iops', vol.iops),
            generate('snapshot_id', vol_snapshot_id),
            generate('vol_state', vol_state_num_value),
        ]

        # only process when there are tags to process
        if vol.tags:
            for _ in vol.tags:
                # Get all of the tags
                output_parts.extend([
                    generate(_.get('Key'), _.get('Value')),
                ])

    # At last put volume state numberic value
    # i.e. 0 (in-use) and 1 (available/unattached) volume
        output_parts.extend([
            generate('state', vol_state_num_value),
        ])

        # output everything at once.
        print ','.join(output_parts)
        #print '{}{}{}'.format('{',output_parts,'}')

if __name__ == '__main__':
    main()

目前它生成的输出如下所示：

vol_id=vol-0abcdab1b68111f8b,az=us-west-2b,vol_type=gp2,size=5,iops=100,snapshot_id=snap-0abcdab1b68111f8b,vol_state=0,mirror=primary,autoscale=true,cluster=customer,Name=[customer-2b-app41] primary,role=app,hostname=customer-2b-app41-i-0abcdab1b68111f8b,state=0
vol_id=vol-0abcdab1b68111f8c,az=us-west-2b,vol_type=gp2,size=12,iops=100,snapshot_id=snap-0abcdab1b68111f9c,vol_state=0,state=0

我正在尝试转换脚本，以便生成 JSON 对象，而不是每行生成 key=value 对 CSV 行。

我尝试使用脚本中所示的 IF 语句来调整脚本，即 isinstance() 用于值部分（用双引号将值括起来，或者如果它是数字则忽略它并使用以下行：

    #if isinstance(value,int):
    #    return '\"{}\": {}'.format(key, value)
    #else:
    #    return '\"{}\": \"{}\"'.format(key, value)

和

    #print '{}{}{}'.format('{',output_parts,'}')

但是，这并没有给我想要的结果。

期望的结果类似于：

{
  {
    "vol_id": "vol-0abcdab1b68111f8b",
    "az": "us-west-2b",
    "vol_type": "gp2",
    "size": 5,
    "iops": 100,
    "snapshot_id":"snap-0abcdab1b68111f8b",
    ...,
    .....,
  },
  {
    "vol_id": "vol-0abcdab1b68111f8c",
    "az": "us-west-2b",
    "vol_type": "gp2",
    "size": 12,
    "iops": 100,
    "snapshot_id": "snap-0abcdab1b68111f9c",
    ...,
    .....
  }
}

我尝试使用json.dumps(output_parts)，但这无助于获得所需的输出。我不需要 CSV 输出。

Answer 1

要将您的csv 行转换为dict，可以这样做：

代码：

def my_csv_to_dict(csv_line):
    return dict(csv.split('=') for csv in csv_line.split(','))

测试代码：

要将这些字典转换为 json，您可以使用 json 库。

test_data = [x.strip() for x in """
    vol_id=vol-0abcdab1b68111f8b,az=us-west-2b,vol_type=gp2,size=5,iops=100,snapshot_id=snap-0abcdab1b68111f8b,vol_state=0,mirror=primary,autoscale=true,cluster=customer,Name=[customer-2b-app41] primary,role=app,hostname=customer-2b-app41-i-0abcdab1b68111f8b,state=0
    vol_id=vol-0abcdab1b68111f8c,az=us-west-2b,vol_type=gp2,size=12,iops=100,snapshot_id=snap-0abcdab1b68111f9c,vol_state=0,state=0
""".split('\n')[1:-1]]

import json
print(json.dumps([my_csv_to_dict(x) for x in test_data], indent=2))

结果：

[
  {
    "az": "us-west-2b", 
    "autoscale": "true", 
    "Name": "[customer-2b-app41] primary", 
    "mirror": "primary", 
    "cluster": "customer", 
    "state": "0", 
    "iops": "100", 
    "role": "app", 
    "vol_type": "gp2", 
    "snapshot_id": "snap-0abcdab1b68111f8b", 
    "vol_id": "vol-0abcdab1b68111f8b", 
    "vol_state": "0", 
    "hostname": "customer-2b-app41-i-0abcdab1b68111f8b", 
    "size": "5"
  }, 
  {
    "az": "us-west-2b", 
    "state": "0", 
    "iops": "100", 
    "vol_type": "gp2", 
    "snapshot_id": "snap-0abcdab1b68111f9c", 
    "vol_id": "vol-0abcdab1b68111f8c", 
    "vol_state": "0", 
    "size": "12"
  }
]