mypy-boto3-rum: CloudWatchRUM Type Stubs

Warnings

• breaking Python 3.8 support has been removed as of `mypy-boto3-builder` version 8.12.0. Ensure your project runs on Python 3.9 or newer.
  Fix: Upgrade your Python environment to 3.9 or a later version.
• breaking The `mypy-boto3` ecosystem migrated to PEP 561 compliant packages with `mypy-boto3-builder` 8.12.0. While largely backward compatible, it changes how type checkers discover stubs. Ensure your `mypy` is up to date.
  Fix: Update your `mypy` installation to the latest version. Verify `mypy` configuration to ensure stub discovery is working correctly.
• breaking Some generated `TypeDef` names were shortened in `mypy-boto3-builder` 8.9.0 (e.g., `CreateDistributionRequestRequestTypeDef` became `CreateDistributionRequestTypeDef`). If you were explicitly importing and using such type definitions, they might have changed.
  Fix: Consult the `mypy-boto3` documentation for the specific service to find the updated `TypeDef` names and adjust your imports accordingly.
• gotcha For optimal code completion and type inference in IDEs like VSCode or PyCharm, it is often recommended to use explicit type annotations for `boto3.client` and `boto3.resource` calls, even though `mypy` might infer them implicitly.
  Fix: Add explicit type annotations for clients, resources, paginators, and waiters (e.g., `client: CloudWatchRUMClient = boto3.client('rum')`).
• gotcha Pylint might raise `undefined-variable` warnings when using `mypy-boto3` stubs with `TYPE_CHECKING` guards.
  Fix: Set type-hinted variables to `object` in the `else` branch of `if TYPE_CHECKING:` blocks to satisfy Pylint.
• gotcha PyCharm users might experience slow performance or high CPU usage due to the complexity of `boto3-stubs`'s literal overloads.
  Fix: Consider installing `boto3-stubs-lite` (if available for CloudWatchRUM) or disabling PyCharm's built-in type checker and relying on `mypy` or `pyright` for checks.

Install

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

Imports

• CloudWatchRUMClient

  from mypy_boto3_rum.client import CloudWatchRUMClient

  Used for explicit type annotation of the boto3 client.
• boto3

  import boto3

  mypy-boto3 stubs enhance the existing `boto3` library; you don't typically import service clients directly from `boto3` in this manner for type checking.

Quickstart

This example demonstrates how to initialize a `boto3` CloudWatchRUM client and use it to list app monitors, benefiting from `mypy-boto3-rum`'s type annotations for improved code completion and static analysis. Explicit type hints are included for better IDE support.

import boto3
from typing import TYPE_CHECKING

# For explicit type hinting, especially helpful for IDEs
if TYPE_CHECKING:
    from mypy_boto3_rum.client import CloudWatchRUMClient
    from mypy_boto3_rum.type_defs import ListAppMonitorsResponseTypeDef


def get_rum_client() -> 'CloudWatchRUMClient':
    """Initializes and returns a typed CloudWatchRUM client."""
    # Mypy will correctly infer the type of 'client' if mypy-boto3-rum is installed
    client: CloudWatchRUMClient = boto3.client('rum')
    return client


def list_rum_app_monitors():
    client = get_rum_client()
    try:
        response: ListAppMonitorsResponseTypeDef = client.list_app_monitors()
        print(f"Found {len(response.get('AppMonitorSummaries', []))} app monitors.")
        for monitor_summary in response.get('AppMonitorSummaries', []):
            print(f"  - {monitor_summary.get('Name')}: {monitor_summary.get('Id')}")
    except client.exceptions.ResourceNotFoundException:
        print("No CloudWatch RUM app monitors found.")
    except Exception as e:
        print(f"An error occurred: {e}")


if __name__ == '__main__':
    # This assumes AWS credentials are configured (e.g., via ~/.aws/credentials or env vars)
    # For a real application, consider explicit region and credentials
    list_rum_app_monitors()