mypy-boto3-greengrass

import boto3 import os from typing import TYPE_CHECKING, Dict, Any # Conditional import for type checking only to avoid runtime dependency # if mypy-boto3-greengrass is not installed in production environments. if TYPE_CHECKING: from mypy_boto3_greengrass.client import GreengrassClient from mypy_boto3_greengrass.type_defs import GetCoreDefinitionResponseTypeDef def get_core_definition_name(core_definition_id: str) -> str: """ Retrieves the name of a Greengrass core definition using type-hinted boto3. Type annotations ensure static analysis correctness. """ # Initialize boto3 client. mypy-boto3 provides stubs for its methods. client = boto3.client("greengrass", region_name=os.environ.get("AWS_REGION", "us-east-1")) # Asserting the client type for static analysis with mypy. # At runtime, 'client' is a regular boto3 client. if TYPE_CHECKING: greengrass_client: GreengrassClient = client response: GetCoreDefinitionResponseTypeDef = greengrass_client.get_core_definition( CoreDefinitionId=core_definition_id ) else: # Runtime execution uses the actual boto3 client without explicit type assertion. # This branch is taken if TYPE_CHECKING is False (e.g., in production). response = client.get_core_definition(CoreDefinitionId=core_definition_id) # Mypy will now correctly check access to 'Name' and its type return response['Name'] if __name__ == "__main__": # For this to make actual AWS calls, ensure AWS_ACCESS_KEY_ID, # AWS_SECRET_ACCESS_KEY (and optionally AWS_REGION) are set in your environment. # Otherwise, it will attempt a call that might fail with an AWS error. print("Note: This example requires AWS credentials for live execution.") print(" To run 'mypy' on this file, ensure 'mypy boto3 mypy-boto3-greengrass' are installed.") print(" Example: 'mypy your_script_name.py'") example_core_id = "your-greengrass-core-definition-id" if os.environ.get("AWS_ACCESS_KEY_ID") and os.environ.get("AWS_SECRET_ACCESS_KEY"): print(f"\nAttempting to get Greengrass Core Definition name for ID: {example_core_id}") try: core_name = get_core_definition_name(example_core_id) print(f"Retrieved Core Definition Name: {core_name}") except Exception as e: print(f"An error occurred during AWS call: {e}") print("Please ensure the Core Definition ID is valid and credentials are correct.") else: print("\nAWS credentials not found. Skipping live AWS call.") print("To test type-checking, you can run 'mypy' on this file without credentials.")