[SOLVED] Sorting a list of ec2 instances python

Issue

I have a python script which prints out a list of ec2 instances as follows :

['i-06db4eb158ad0bdfd,2021-05-12 12:04:19+00:00,False', 'i-0f67cf99fb4536c3f,2020-10-14 13:32:23+00:00,asg-elk-', 'i-0539c8dfc839cbfda,2020-10-26 07:38:01+00:00,asg-standalone', 'i-0f285277529543462,2018-05-18 16:47:00+00:00,False', 'i-0d649cebdf54bd2f4,2020-03-12 10:07:07+00:00,asg-ddf', 'i-01734dfef0159c5c8,2020-10-20 13:05:27+00:00,asg-pro', 'i-0ff596f1dc01b61d8,2021-03-17 11:21:21+00:00,asg-base-test']

I want to be able to sort the list out based on CreationDateTime. I have used the python built-in function sorted() but that doesn't seem to be giving me the output i need.

My python script is as follows :

    response = ec2_client.describe_instances(
        MaxResults=10
    ) 
    instances = (len(response['Reservations']))

    instances_list = []
    for x in range(instances):

        # Get InstanceId
        instance_id = (response['Reservations'][x]
                       ['Instances'][0]['InstanceId'])
        # Get NetworkInterfacws AttatchTime
        network_interface_id = (
            response['Reservations'][x]['Instances'][0]['NetworkInterfaces'][0]['NetworkInterfaceId'])
        network_interface_details = ec2_client.describe_network_interfaces(
            NetworkInterfaceIds=[network_interface_id])
        networkinterface_id_attachedtime = network_interface_details[
            'NetworkInterfaces'][0]['Attachment']['AttachTime']
  

        # print results
        
       line = '{},{},{}'.format(
                instance_id, networkinterface_id_attachedtime, autoscaling_group_name)
            instances_list.append(line)
            sorted(instances_list)

Solution

sorted takes key argument which you can use to sort by date with a lambda:

sorted(instances_list, key=lambda v: v.split(',')[1])

Answered By - Marcin