def download_image_from_s3()

in source/lambda_function.py [0:0]

• 22 lines of code
• 7 McCabe index (conditional complexity)

def download_image_from_s3(presigned_s3_url):

    REKOGNITION_MAX_FILE_SIZE = 5242880
    response = http.request('GET', presigned_s3_url)

    if response is None:
       raise ValueError('response is empty')
    if response.headers is None:
       raise ValueError('response has no headers')

    if response.status >= 300:

        s3_error_code, s3_error_message = parse_s3_error_response(response.data.decode('utf-8'))

        raise S3GetException( 
            s3_http_code = response.status, 
            s3_error_code = s3_error_code, 
            s3_error_message = "S3 Error: " + s3_error_message
            )
    
    extensions = ['/jpg', '/jpeg', '/png']
    if not any(response.headers['Content-Type'].lower().endswith(ext) for ext in extensions):
        raise UnsupportedFormatException()
    file_format = response.headers['Content-Type'].split('/')[-1]
    
    if int(response.headers['Content-Length']) > REKOGNITION_MAX_FILE_SIZE:
        raise ExceedingFileSizeException()

    # Translate the headers returned from the presigned s3 url request to a format used by 
    # S3 WriteGetObjectResponse.
    headers = translate_response_headers_to_writegetobjectresponse(response.headers)

    return response.data, headers, file_format