mypy-boto3-appmesh

Warnings

• breaking Python 3.8 is no longer supported by `mypy-boto3-builder` (version 8.12.0 and above), which generates `mypy-boto3-appmesh`.
  Fix: Upgrade to Python 3.9 or newer.
• breaking Type definition (TypedDict) naming conventions changed in `mypy-boto3-builder`. Shorter names are used, and 'Extra' postfixes moved, which can break existing explicit `TypeDef` imports.
  Fix: Review and update `TypeDef` import paths and names in your codebase according to the new conventions.
• gotcha This package only provides type annotations. The `boto3` library itself must be installed in your environment for runtime execution of AWS API calls.
  Fix: Always install `boto3` alongside `mypy-boto3-appmesh` (e.g., `pip install mypy-boto3-appmesh boto3`).
• gotcha For Pylint compatibility, if `mypy-boto3-appmesh` is a dev-only dependency, Pylint may complain about undefined variables. Using `if TYPE_CHECKING:` guards around imports helps.
  Fix: Wrap type imports in a `if TYPE_CHECKING:` block, and optionally define `object` aliases for non-type-checking environments.
• gotcha Some IDEs (like VSCode with certain extensions) might require explicit type annotations for `boto3.client()` and `boto3.resource()` calls to provide full autocomplete and type checking, even if `mypy` itself can infer them.
  Fix: Explicitly annotate your client and resource objects, e.g., `client: AppMeshClient = session.client("appmesh")`.
• gotcha When passing dictionaries as arguments to boto3 methods, ensure they match the generated `TypedDict` structure. Mypy will flag direct dictionaries as type mismatches if not explicitly cast or constructed as the `TypedDict`.
  Fix: Import and use the specific `RequestTypeDef` for method arguments, either by constructing a dictionary matching its shape or by using a type cast.

Install

• pip install mypy-boto3-appmesh boto3 Install with pip

Imports

• AppMeshClient

  from mypy_boto3_appmesh import AppMeshClient

  Import the typed client for boto3.client('appmesh')
• AppMeshServiceResource

  from mypy_boto3_appmesh import AppMeshServiceResource

  Import the typed service resource for boto3.resource('appmesh')
• ListMeshesResponseTypeDef

  from mypy_boto3_appmesh.type_defs import ListMeshesResponseTypeDef

  Import specific TypedDicts for explicit response type hinting.

Quickstart

This example demonstrates how to initialize a typed AppMesh client and use it to list existing meshes. Type hints provide autocompletion and static analysis for client methods and their responses. The `TYPE_CHECKING` guard ensures `mypy-boto3-appmesh` is only a development dependency.

import os
from typing import TYPE_CHECKING
import boto3

if TYPE_CHECKING:
    from mypy_boto3_appmesh import AppMeshClient
    from mypy_boto3_appmesh.type_defs import ListMeshesResponseTypeDef

# Ensure AWS credentials are configured (e.g., via environment variables or ~/.aws/credentials)
# For example:
# os.environ['AWS_ACCESS_KEY_ID'] = os.environ.get('AWS_ACCESS_KEY_ID', 'YOUR_ACCESS_KEY')
# os.environ['AWS_SECRET_ACCESS_KEY'] = os.environ.get('AWS_SECRET_ACCESS_KEY', 'YOUR_SECRET_KEY')
# os.environ['AWS_REGION'] = os.environ.get('AWS_REGION', 'us-east-1')

def list_app_meshes() -> None:
    session = boto3.Session()
    client: AppMeshClient = session.client("appmesh")

    try:
        # Using explicit type annotation for the response for demonstration
        response: ListMeshesResponseTypeDef = client.list_meshes()
        print("App Mesh Meshes:")
        for mesh in response.get("meshes", []):
            print(f"  - {mesh.get('meshName')}")
    except Exception as e:
        print(f"Error listing App Meshes: {e}")

if __name__ == "__main__":
    list_app_meshes()