mypy-boto3-appflow

Common errors

• ModuleNotFoundError: No module named 'mypy_boto3_appflow'

  cause The `mypy-boto3-appflow` stub package is either not installed in your environment or not accessible by your Python interpreter/mypy configuration.
  fix Install the package using pip: `python -m pip install mypy-boto3-appflow` or, if using `boto3-stubs`, install with the appflow extra: `python -m pip install 'boto3-stubs[appflow]'`.

• error: Module has no attribute "client"  (or similar AttributeError for boto3 client methods)

  cause Mypy is not correctly inferring the type of `boto3.client("appflow")` because the `mypy-boto3-appflow` stubs are not being recognized or explicitly used, leading to `boto3.client` returning an `Any` type or a generic `Client` type without specific Appflow methods.
  fix Ensure `mypy-boto3-appflow` is installed and mypy is configured to find stubs. Explicitly annotate the client: `from mypy_boto3_appflow.client import AppflowClient; client: AppflowClient = boto3.client("appflow")`.

• error: Argument "<param_name>" to "<method_name>" has incompatible type "Dict[str, Any]"; expected "<SomeAppflowTypedDict>TypeDef"

  cause You are passing a plain Python dictionary (`Dict[str, Any]`) as an argument to an Appflow client method, but `mypy-boto3-appflow` expects a specific `TypedDict` from its stubs for better type checking.
  fix Import and use the correct `TypedDict` from `mypy_boto3_appflow.type_defs` for the method's parameters. For example, `from mypy_boto3_appflow.type_defs import CreateFlowRequestRequestTypeDef; request: CreateFlowRequestRequestTypeDef = {...}; client.create_flow(**request)`.

• Pylint complains about undefined variables when using TYPE_CHECKING

  cause Pylint, unlike mypy, processes the `if TYPE_CHECKING:` block even when type checking is not active, leading it to flag variables defined only within that block as undefined at runtime.
  fix Add `else` branches to define fallback types (e.g., `object`) for runtime, or configure Pylint to ignore these specific warnings. Example: `if TYPE_CHECKING: from mypy_boto3_appflow.client import AppflowClient else: AppflowClient = object`.

Warnings

• breaking Support for Python 3.8 was removed in `mypy-boto3-builder` version 8.12.0 (which generates `mypy-boto3-appflow` versions 1.42.x onwards). Packages now require Python 3.9 or newer.
  Fix: Upgrade your Python environment to 3.9 or newer if you are using recent versions of `mypy-boto3-appflow`.
• breaking TypeDef naming conventions changed in `mypy-boto3-builder` version 8.9.0. This might affect code that explicitly imports or references TypeDefs with previously conflicting or redundant naming patterns (e.g., `CreateDistributionRequestRequestTypeDef` becoming `CreateDistributionRequestTypeDef`).
  Fix: Review your codebase for explicit TypeDef imports and adjust names according to the updated conventions. Common changes include shorter names for packed method arguments and `Extra` postfix moving to the end of the name.
• gotcha This package (`mypy-boto3-appflow`) provides *only* type stubs for the Appflow service. It does not include the actual runtime `boto3` library. You must install `boto3` separately for your code to function.
  Fix: Always install `boto3` alongside `mypy-boto3-appflow` (e.g., `pip install boto3 mypy-boto3-appflow`).
• gotcha Your `boto3` environment must be configured with a default AWS region, either through environment variables (AWS_REGION, AWS_DEFAULT_REGION), shared configuration files, or by explicitly passing it to `boto3.client`/`Session` when initializing.
  Fix: Ensure your AWS environment or `boto3` client initialization includes a specified region (e.g., set `AWS_REGION` environment variable or pass `region_name='us-east-1'` to `boto3.client`).
• gotcha Your Boto3 client requires an AWS region to be specified. This can be done via environment variables (AWS_DEFAULT_REGION or AWS_REGION), AWS config files, or by passing the 'region_name' argument to the client constructor. If no region is specified, Boto3 operations will fail.
  Fix: Ensure an AWS region is configured for your Boto3 client by setting environment variables, configuring AWS CLI/SDK, or explicitly passing 'region_name' when creating Boto3 clients.

Install

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

Imports

• AppflowClient

  from mypy_boto3_appflow.client import AppflowClient

• ListFlowsResponseTypeDef

  from mypy_boto3_appflow.type_defs import ListFlowsResponseTypeDef

Quickstart

This quickstart demonstrates how to use `mypy-boto3-appflow` to add type hints to a `boto3` Appflow client. It initializes an Appflow client, calls `list_flows` with type-annotated variables, and prints flow details. Ensure `boto3` is also installed and AWS credentials are configured.

import boto3
from mypy_boto3_appflow.client import AppflowClient
from mypy_boto3_appflow.type_defs import ListFlowsResponseTypeDef

def get_appflow_flows() -> ListFlowsResponseTypeDef:
    # mypy-boto3-appflow provides type hints for the boto3 client
    client: AppflowClient = boto3.client('appflow')
    response: ListFlowsResponseTypeDef = client.list_flows()
    for flow in response.get('flows', []):
        print(f"Flow Name: {flow.get('flowName')}, ARN: {flow.get('flowArn')}")
    return response

if __name__ == '__main__':
    # This example requires AWS credentials configured (e.g., via ~/.aws/credentials
    # or environment variables like AWS_ACCESS_KEY_ID, AWS_SECRET_ACCESS_KEY).
    # It will attempt to list Appflow flows in the configured region.
    try:
        print("Listing Appflow flows...")
        get_appflow_flows()
        print("Finished listing Appflow flows.")
    except Exception as e:
        print(f"An error occurred: {e}")