Type annotations for boto3 AppRunner

Warnings

• breaking Python 3.8 support was removed starting with `mypy-boto3-builder` version 8.12.0. Users on Python 3.8 or older will need to upgrade their Python version to use recent `mypy-boto3` packages.
  Fix: Upgrade Python to 3.9 or newer.
• breaking The `mypy-boto3-builder` version 8.9.0 introduced breaking changes to generated TypeDef names. Specifically, arguments for methods may use shorter names, and 'Extra' postfixes were moved to the end of conflicting TypeDef names (e.g., `CreateDistributionRequestRequestTypeDef` -> `CreateDistributionRequestTypeDef`). If you were directly referencing generated TypeDef names, these might have changed.
  Fix: Update imports and references to TypeDefs according to the new naming conventions. Use IDE autocompletion to find the correct names.
• gotcha While `boto3-stubs` (the umbrella project) offers implicit type annotations, explicit type annotations for `boto3.client` and `boto3.session.client` calls are often recommended for the best experience with IDEs (like VSCode, PyCharm) and strict `mypy` configurations.
  Fix: Always explicitly type-hint your `boto3` client variables, e.g., `client: AppRunnerClient = boto3.client('apprunner')`.
• gotcha This package provides *type annotations* for `boto3`'s AppRunner client. It does not include `boto3` itself. You must install `boto3` separately for your code to run at runtime.
  Fix: Ensure `boto3` is installed alongside `mypy-boto3-apprunner` (e.g., `pip install boto3 mypy-boto3-apprunner`).
• gotcha When using `if TYPE_CHECKING:` to conditionally import type hints, `pylint` may incorrectly report 'undefined variable' warnings. This can be mitigated by assigning `object` to the type aliases in the `else` branch.
  Fix: Implement an `else` branch in `if TYPE_CHECKING:` blocks to assign `object` to your type aliases (e.g., `else: AppRunnerClient = object`).

Install

• pip install boto3 mypy mypy-boto3-apprunner Install boto3, mypy, and AppRunner stubs

Imports

• AppRunnerClient

  from mypy_boto3_apprunner.client import AppRunnerClient

  Client types are provided by `mypy-boto3-apprunner`, not directly from `boto3` or `botocore`.
• ServiceSummaryTypeDef

  from mypy_boto3_apprunner.type_defs import ServiceSummaryTypeDef

  Specific type definitions (TypedDicts) are imported from the `mypy_boto3_apprunner.type_defs` submodule.

Quickstart

This quickstart demonstrates how to use `mypy-boto3-apprunner` to provide type hints for the AppRunner client. It fetches a list of AppRunner services, leveraging the `AppRunnerClient` type for autocompletion and static analysis. The `TYPE_CHECKING` guard ensures the type-only imports don't introduce runtime dependencies.

import boto3
from typing import TYPE_CHECKING

if TYPE_CHECKING:
    from mypy_boto3_apprunner.client import AppRunnerClient
    from mypy_boto3_apprunner.type_defs import ServiceSummaryTypeDef


def get_apprunner_services() -> list['ServiceSummaryTypeDef']:
    client: AppRunnerClient = boto3.client("apprunner")
    response = client.list_services(
        MaxResults=5, 
        NextToken=None # Use actual token for pagination in real apps
    )
    return response.get("ServiceSummaryList", [])


if __name__ == "__main__":
    # This code block will run at runtime, but only if boto3 is configured.
    # For type checking, mypy will use the stubs.
    # Ensure AWS credentials are set up (e.g., via AWS_ACCESS_KEY_ID, AWS_SECRET_ACCESS_KEY, AWS_REGION_NAME env vars)
    # or ~/.aws/credentials and ~/.aws/config
    try:
        services = get_apprunner_services()
        print(f"Found {len(services)} AppRunner services:")
        for service in services:
            print(f"  - {service['ServiceName']} (Status: {service['Status']})")
    except Exception as e:
        print(f"Error fetching AppRunner services: {e}")