title: How to I access Security token for Python SDK boto3
body: <p>I want to access AWS comprehend api from python script. Not getting any leads of how do I remove this error. One thing I know that I have to get session security token.</p>
  
  <pre><code>try:
    client = boto3.client(service_name='comprehend', region_name='us-east-1', aws_access_key_id='KEY ID', aws_secret_access_key= 'ACCESS KEY')
    text = "It is raining today in Seattle"
    print('Calling DetectEntities')
    print(json.dumps(client.detect_entities(Text=text, LanguageCode='en'), sort_keys=True, indent=4))
    print('End of DetectEntities\n')
  
  except ClientError as e:
    print (e)
  </code></pre>
  
  <blockquote>
    <p>Error : An error occurred (UnrecognizedClientException) when calling the DetectEntities operation: The security token included in the request is invalid.</p>
  </blockquote>