Mypy Boto3 SNS Type Stubs

Warnings

• breaking Removed support for Python 3.8. The `mypy-boto3-builder` 8.12.0, which generated `mypy-boto3-sns` 1.42.3, no longer supports Python 3.8. Users on Python 3.8 must either upgrade their Python version or use an older version of `mypy-boto3-sns`.
  Fix: Upgrade to Python 3.9 or higher. If unable to upgrade Python, pin `mypy-boto3-sns` to an older compatible version.
• breaking Breaking changes to `TypeDef` naming conventions. In `mypy-boto3-builder` 8.9.0 (and potentially affecting later versions), `TypeDef` names for packed method arguments were shortened (e.g., `CreateDistributionRequestRequestTypeDef` became `CreateDistributionRequestTypeDef`). Additionally, conflicting `Extra` postfixes were moved to the end of the name (e.g., `CreateDistributionExtraRequestTypeDef` became `CreateDistributionRequestExtraTypeDef`). While not specific to SNS in the release notes, this applies to `[services]` generated by the builder and may affect users relying on specific `TypeDef` names.
  Fix: Review your code for direct imports or usage of `TypeDef` names and update them according to the new naming conventions. Consult the specific service's documentation for exact new names.
• gotcha The library only provides type hints; it does not add runtime functionality to `boto3`. `mypy-boto3-sns` is a stub package that helps static type checkers (like mypy) understand `boto3`'s API. It is not a replacement for `boto3` and has no runtime impact on your application.
  Fix: Ensure `boto3` is installed alongside `mypy-boto3-sns`. Do not expect `mypy-boto3-sns` to provide actual AWS SDK functionality.
• gotcha `pylint` may complain about undefined variables when using `typing.TYPE_CHECKING` for conditional imports. This is a known issue.
  Fix: Set all types to `object` in the `else` block for `if TYPE_CHECKING:` statements to provide a fallback for `pylint`. Example: `if TYPE_CHECKING: from mypy_boto3_sns.client import SNSClient else: SNSClient = object`
• gotcha There are two main ways to install boto3 stubs: `mypy-boto3-sns` (standalone) or `boto3-stubs[sns]` (part of the `boto3-stubs` meta-package). Confusing these or mixing installations can lead to unexpected type-checking behavior.
  Fix: Choose one installation strategy and stick to it. For individual service stubs, `pip install mypy-boto3-sns` is appropriate. For a more integrated approach, `pip install 'boto3-stubs[sns]'` is another option.

Install

• pip install mypy-boto3-sns boto3 mypy Install with Boto3 and Mypy

Imports

• SNSClient

  from mypy_boto3_sns.client import SNSClient

  For explicit type annotations of the SNS client.
• SNSServiceResource

  from mypy_boto3_sns.service_resource import SNSServiceResource

  For explicit type annotations of the SNS service resource.
• AddPermissionInputTopicAddPermissionTypeDef

  from mypy_boto3_sns.type_defs import AddPermissionInputTopicAddPermissionTypeDef

  For explicit type annotations of specific TypeDefs, often used for method arguments.

Quickstart

This example demonstrates how to obtain an SNS client with and without explicit type annotations using `mypy-boto3-sns`. Type annotations are primarily for static analysis tools during development, not for runtime execution. The `TYPE_CHECKING` block shows how `mypy` would verify types.

import boto3
from typing import TYPE_CHECKING
from mypy_boto3_sns.client import SNSClient

# Boto3 client without explicit type annotation (type checker will infer)
def get_sns_client_inferred():
    return boto3.client("sns")

# Boto3 client with explicit type annotation (recommended for type checking)
def get_sns_client_typed() -> SNSClient:
    return boto3.client("sns")

if TYPE_CHECKING:
    # Example usage with type checking
    sns_client: SNSClient = get_sns_client_typed()
    response = sns_client.publish(TopicArn="arn:aws:sns:REGION:ACCOUNT:TOPIC", Message="Hello, SNS!")
    print(f"Message ID: {response['MessageId']}")

# Normal runtime usage (type hints are ignored by the interpreter)
sns_client_runtime = get_sns_client_inferred()
# You would typically have actual topic/message data here, 
# but for a quickstart, we keep it simple.
# Replace with a valid TopicArn for actual execution.
# response_runtime = sns_client_runtime.publish(TopicArn="arn:aws:sns:REGION:ACCOUNT:TOPIC", Message="Hello from runtime!")
# print(f"Runtime Message ID: {response_runtime['MessageId']}")