AWS Cloudformation，使用 Python 从键中获取值的最佳方法 3

Question

I have a Cloudformation template with that defines the following output values:

Outputs:
  AccessKeyForUser:
    Value:
      !Ref CFNKeys
  SecretAccessKeyForUser:
    Value: !GetAtt CFNKeys.SecretAccessKey

In Python 3 with boto3, I currently get the output values this way:

session = boto3.session.Session()
cf_resource = session.resource('cloudformation')
stack = cf_resource.Stack(stackname)

code_commit_access_key = next(filter(lambda x: x['OutputKey'] == 'AccessKeyForUser', stack.outputs))['OutputValue']
code_commit_access_secret = next(filter(lambda x: x['OutputKey'] == 'SecretAccessKeyForUser', stack.outputs))['OutputValue']

I think that's not the best way. Is there a better way to get the output values?

Answer 1

So what you actually want is to have a dictionary you can query for all keys you're interested in. So let's just create one using a dict comprehension , which is probably the shortest while still pythonic way to implement this:

cf_resource = boto3.resource("cloudformation")
stack = cf_resource.Stack(stackname)

outputs = {output["OutputKey"]: output["OutputValue"] for output in stack.outputs}

code_commit_access_key = outputs["AccessKeyForUser"]
code_commit_access_secret = outputs["SecretAccessKeyForUser"]

Please note that this could result in unexpected results if stack.outputs would contain multiple items with the same OutputKey , as you would only get the latest of such items represented in the dictionary. However I believe this isn't something to worry about in this particular case, as CloudFormation output value names have to be unique anyway.