Boto3 - Print AWS Instance Average CPU Utilization

Question

I am trying to print out just the averaged CPU utilization of an AWS instance. This code will print out the 'response' but the for loop at the end isn't printing the averaged utilization. Could someone assist? Thank you in advance!

    import boto3
    import sys
    from datetime import datetime, timedelta
        client = boto3.client('cloudwatch')
        response = client.get_metric_statistics(
            Namespace='AWS/EC2',
            MetricName='CPUUtilization',
            Dimensions=[
                {
                'Name': 'InstanceId',
                'Value': 'i-1234abcd'
                },
            ],
            StartTime=datetime(2018, 4, 23) - timedelta(seconds=600),
            EndTime=datetime(2018, 4, 24),
            Period=86400,
            Statistics=[
                'Average',
            ],
            Unit='Percent'
        )
    for cpu in response:
        if cpu['Key'] == 'Average':
            k = cpu['Value']
    print(k)

This is the error message I am getting:

    Traceback (most recent call last):
      File "C:\bin\TestCW-CPU.py", line 25, in <module>
        if cpu['Key'] == 'Average':
    TypeError: string indices must be integers

Answer 1

for cpu in response['Datapoints']:
  if 'Average' in cpu:
    print(cpu['Average'])

2.25348611111
2.26613194444

You can see why this works, if you print the value of cpu:

print(response)

for cpu in response['Datapoints']:
  print(cpu)

{u'Timestamp': datetime.datetime(2018, 4, 23, 23, 50, tzinfo=tzlocal()), u'Average': 2.2534861111111106, u'Unit': 'Percent'}
{u'Timestamp': datetime.datetime(2018, 4, 22, 23, 50, tzinfo=tzlocal()), u'Average': 2.266131944444444, u'Unit': 'Percent'}

Answer 2

This will output the average CPU:

    for k, v in response.items():
        if k == 'Datapoints':
        for y in v:
            print(y['Average'])