Type Annotations for boto3 MemoryDB

Warnings

• breaking Python 3.8 support has been removed in `mypy-boto3-builder` version 8.12.0, which generates `mypy-boto3-memorydb`. Consequently, this package (1.42.3 and newer) requires Python 3.9 or higher.
  Fix: Upgrade your Python environment to 3.9 or newer.
• breaking Breaking changes were introduced in `mypy-boto3-builder` 8.9.0 regarding TypeDef naming conventions. TypeDefs for packed method arguments use shorter names (e.g., `CreateDistributionRequestRequestTypeDef` -> `CreateDistributionRequestTypeDef`), and conflicting `Extra` postfixes were moved (e.g., `CreateDistributionExtraRequestTypeDef` -> `CreateDistributionRequestExtraTypeDef`). This may require updates to existing type hints.
  Fix: Review and update your TypeDef imports and usages according to the new naming conventions. Refer to the specific service's `type_defs` documentation.
• gotcha This package provides *only type stubs*. You must install the `boto3` library separately for your code to run correctly. `mypy` is also required for static type checking.
  Fix: Ensure `boto3` and `mypy` are installed: `pip install boto3 mypy`.
• gotcha For PyCharm users, if you experience slow performance due to `Literal` overloads, it is recommended to use the `boto3-stubs-lite` alternative, which provides a more RAM-friendly experience at the cost of requiring more explicit type annotations.
  Fix: Install `boto3-stubs-lite[memorydb]` instead: `pip install 'boto3-stubs-lite[memorydb]' boto3`.
• gotcha For optimal auto-completion and type checking in IDEs like VSCode or with older `mypy` versions, it's often necessary to use explicit type annotations for `boto3.client()` calls, as shown in the quickstart.
  Fix: Explicitly annotate `boto3.client()` return values with the corresponding `mypy-boto3-service.client` type (e.g., `client: MemoryDBClient = boto3.client('memorydb')`).
• gotcha The version of `mypy-boto3-memorydb` (e.g., 1.42.3) indicates the `boto3` version it provides stubs for. However, the underlying `mypy-boto3-builder` version (e.g., 8.12.0) is independent and refers to the builder's own release cycle and features.
  Fix: When troubleshooting or reporting issues, be aware of both version numbers. The package version correlates to the `boto3` version, while the builder version indicates the generator's capabilities.

Install

• pip install mypy-boto3-memorydb boto3 mypy Install standalone package
• pip install 'boto3-stubs[memorydb]' boto3 mypy Install via boto3-stubs extra

Imports

• MemoryDBClient

  from mypy_boto3_memorydb.client import MemoryDBClient

• DescribeClustersPaginator

  from mypy_boto3_memorydb.paginator import DescribeClustersPaginator

• ResponseMetadataTypeDef

  from mypy_boto3_memorydb.type_defs import ResponseMetadataTypeDef

  Type definitions are in the `type_defs` submodule, not directly under `client`.
• MemoryDBServiceName

  from mypy_boto3_memorydb.literals import MemoryDBServiceName

Quickstart

This quickstart demonstrates how to initialize a MemoryDB client with type annotations. The `TYPE_CHECKING` block ensures that the type imports are only used by the type checker and do not introduce runtime dependencies. The client object `client` is explicitly annotated with `MemoryDBClient` for full type-checking and IDE auto-completion. This example creates a MemoryDB cluster.

import boto3
from typing import TYPE_CHECKING

if TYPE_CHECKING:
    from mypy_boto3_memorydb.client import MemoryDBClient
    from mypy_boto3_memorydb.type_defs import CreateClusterResponseTypeDef


def create_memorydb_cluster(cluster_name: str, node_type: str, num_shards: int) -> CreateClusterResponseTypeDef:
    client: MemoryDBClient = boto3.client("memorydb")
    response = client.create_cluster(
        ClusterName=cluster_name,
        NodeType=node_type,
        NumShards=num_shards,
        Engine="redis",
        SnapshotRetentionLimit=7,
        SubnetGroupName='default',
        ParameterGroupName='default.memorydb.redis6'
    )
    print(f"Created MemoryDB cluster: {response['Cluster']['ClusterName']}")
    return response

# Example usage (ensure you have AWS credentials configured)
# create_memorydb_cluster("my-test-cluster", "db.r6g.large", 1)