mypy-boto3-elbv2

Warnings

• breaking Support for Python 3.8 was removed in `mypy-boto3-builder` version 8.12.0. Users on Python 3.8 or older must upgrade to Python 3.9 or newer.
  Fix: Upgrade your Python environment to 3.9 or a newer supported version.
• breaking Version 8.9.0 of `mypy-boto3-builder` introduced breaking changes in TypeDef naming conventions. Specifically, TypeDefs for packed method arguments use shorter names (`CreateDistributionRequestRequestTypeDef` -> `CreateDistributionRequestTypeDef`), and conflicting `Extra` postfixes were moved to the end (`CreateDistributionExtraRequestTypeDef` -> `CreateDistributionRequestExtraTypeDef`).
  Fix: Review and update any custom code directly referencing affected `TypeDef` names.
• gotcha For optimal IDE autocompletion and type checking, especially when using `mypy-boto3-elbv2` as a standalone package or `boto3-stubs-lite`, it is often necessary to explicitly annotate the client type (e.g., `client: ElasticLoadBalancingv2Client = boto3.client("elbv2")`). While `boto3-stubs` (the meta-package) aims for implicit type discovery, explicit annotations provide the most reliable experience.
  Fix: Use explicit type annotations for boto3 clients, resources, paginators, and waiters, especially when passing them between functions or storing them.
• gotcha The version of `mypy-boto3-elbv2` is synchronized with the `boto3` version it provides stubs for (e.g., `mypy-boto3-elbv2 1.42.3` corresponds to `boto3 1.42.3`). Ensure your `mypy-boto3-elbv2` version matches or is compatible with your installed `boto3` version to avoid type checking inconsistencies.
  Fix: Align `mypy-boto3-elbv2` installation with your `boto3` installation. The recommended `boto3-stubs[elbv2]` installation method helps manage this.
• deprecated The original `mypy-boto3` top-level package is considered legacy. While `mypy-boto3-elbv2` (the service-specific stub) is still actively maintained and generated by `mypy-boto3-builder`, users are encouraged to use the `boto3-stubs` or `types-boto3` packages (e.g., `pip install 'boto3-stubs[elbv2]'`) for a more consolidated and officially recommended approach to type annotations.
  Fix: Consider migrating to `boto3-stubs` or `types-boto3` if you are managing type annotations for multiple boto3 services.

Install

• pip install mypy-boto3-elbv2 Standalone installation
• pip install 'boto3-stubs[elbv2]' Recommended: As part of boto3-stubs

Imports

• ElasticLoadBalancingv2Client

  from mypy_boto3_elbv2.client import ElasticLoadBalancingv2Client

• DescribeLoadBalancersOutputTypeDef

  from mypy_boto3_elbv2.type_defs import DescribeLoadBalancersOutputTypeDef

Quickstart

This quickstart demonstrates how to initialize a type-hinted ELBv2 client and use it to describe load balancers, leveraging the provided type definitions for improved code quality and IDE support.

import boto3
from mypy_boto3_elbv2.client import ElasticLoadBalancingv2Client
from mypy_boto3_elbv2.type_defs import DescribeLoadBalancersOutputTypeDef

def get_elbv2_client() -> ElasticLoadBalancingv2Client:
    """Returns a typed ELBv2 client."""
    # boto3-stubs provides auto-discovery for Session.client
    # For standalone mypy-boto3-elbv2, explicit typing is recommended.
    client: ElasticLoadBalancingv2Client = boto3.client("elbv2")
    return client

def list_load_balancers():
    client = get_elbv2_client()
    try:
        response: DescribeLoadBalancersOutputTypeDef = client.describe_load_balancers()
        for lb in response.get("LoadBalancers", []):
            print(f"Load Balancer ARN: {lb['LoadBalancerArn']}, Name: {lb['LoadBalancerName']}")
    except client.exceptions.LoadBalancerNotFoundException:
        print("No load balancers found.")
    except Exception as e:
        print(f"An error occurred: {e}")

if __name__ == "__main__":
    list_load_balancers()