momento 0.22.0

SDK for Momento

Momento Python Client Library

Python client SDK for Momento Serverless Cache: a fast, simple, pay-as-you-go caching solution without any of the operational overhead required by traditional caching solutions!

Getting Started :running:

Requirements

• Python 3.7 or above is required
• A Momento Auth Token is required, you can generate one using the Momento CLI

Examples

Ready to dive right in? Just check out the examples directory for complete, working examples of how to use the SDK.

Installation

The Momento SDK is available on PyPi. To install via pip:

pip install momento

Usage

Here is a quickstart you can use in your own project:

import logging
from datetime import timedelta

from example_utils.example_logging import initialize_logging

from momento import SimpleCacheClient
from momento.auth import CredentialProvider
from momento.config import Laptop
from momento.responses import CacheGet, CacheSet, CreateCache, ListCaches

_AUTH_PROVIDER = CredentialProvider.from_environment_variable("MOMENTO_AUTH_TOKEN")
_CACHE_NAME = "cache"
_ITEM_DEFAULT_TTL_SECONDS = timedelta(seconds=60)
_KEY = "MyKey"
_VALUE = "MyValue"

_logger = logging.getLogger("momento-example")


def _print_start_banner() -> None:
    _logger.info("******************************************************************")
    _logger.info("*                      Momento Example Start                     *")
    _logger.info("******************************************************************")


def _print_end_banner() -> None:
    _logger.info("******************************************************************")
    _logger.info("*                       Momento Example End                      *")
    _logger.info("******************************************************************")


def _create_cache(cache_client: SimpleCacheClient, cache_name: str) -> None:
    create_cache_response = cache_client.create_cache(cache_name)
    match create_cache_response:
        case CreateCache.Success():
            pass
        case CreateCache.CacheAlreadyExists():
            _logger.info(f"Cache with name: {cache_name!r} already exists.")
        case CreateCache.Error() as error:
            _logger.error(f"Error creating cache: {error.message}")
        case _:
            _logger.error("Unreachable")


def _list_caches(cache_client: SimpleCacheClient) -> None:
    _logger.info("Listing caches:")
    list_caches_response = cache_client.list_caches()
    while True:
        match list_caches_response:
            case ListCaches.Success() as success:
                for cache_info in success.caches:
                    _logger.info(f"- {cache_info.name!r}")
                next_token = success.next_token
                if next_token is None:
                    break
            case ListCaches.Error() as error:
                _logger.error(f"Error creating cache: {error.message}")
            case _:
                _logger.error("Unreachable")

        list_caches_response = cache_client.list_caches(next_token)
    _logger.info("")


if __name__ == "__main__":
    initialize_logging()
    _print_start_banner()
    with SimpleCacheClient(Laptop.latest(), _AUTH_PROVIDER, _ITEM_DEFAULT_TTL_SECONDS) as cache_client:
        _create_cache(cache_client, _CACHE_NAME)
        _list_caches(cache_client)

        _logger.info(f"Setting Key: {_KEY!r} Value: {_VALUE!r}")
        set_response = cache_client.set(_CACHE_NAME, _KEY, _VALUE)
        match set_response:
            case CacheSet.Success():
                pass
            case CacheSet.Error() as error:
                _logger.error(f"Error creating cache: {error.message}")
            case _:
                _logger.error("Unreachable")

        _logger.info(f"Getting Key: {_KEY!r}")
        get_response = cache_client.get(_CACHE_NAME, _KEY)
        match get_response:
            case CacheGet.Hit() as hit:
                _logger.info(f"Look up resulted in a hit: {hit}")
                _logger.info(f"Looked up Value: {hit.value_string!r}")
            case CacheGet.Miss():
                _logger.info("Look up resulted in a: miss. This is unexpected.")
            case CacheGet.Error() as error:
                _logger.error(f"Error creating cache: {error.message}")
            case _:
                _logger.error("Unreachable")
    _print_end_banner()

Note 1: the above code requires an environment variable named MOMENTO_AUTH_TOKEN which must be set to a valid Momento authentication token.

Note 2: The above code uses structural pattern matching, a feature introduced in Python 3.10. Using a Python version less than 3.10? No problem. Here is the same example compatible across all versions of Python:

import logging
from datetime import timedelta

from example_utils.example_logging import initialize_logging

from momento import SimpleCacheClient
from momento.auth import CredentialProvider
from momento.config import Laptop
from momento.responses import CacheGet, CacheSet, CreateCache, ListCaches

_AUTH_PROVIDER = CredentialProvider.from_environment_variable("MOMENTO_AUTH_TOKEN")
_CACHE_NAME = "cache"
_ITEM_DEFAULT_TTL_SECONDS = timedelta(seconds=60)
_KEY = "MyKey"
_VALUE = "MyValue"

_logger = logging.getLogger("momento-example")


def _print_start_banner() -> None:
    _logger.info("******************************************************************")
    _logger.info("*                      Momento Example Start                     *")
    _logger.info("******************************************************************")


def _print_end_banner() -> None:
    _logger.info("******************************************************************")
    _logger.info("*                       Momento Example End                      *")
    _logger.info("******************************************************************")


def _create_cache(cache_client: SimpleCacheClient, cache_name: str) -> None:
    create_cache_response = cache_client.create_cache(cache_name)
    if isinstance(create_cache_response, CreateCache.Success):
        pass
    elif isinstance(create_cache_response, CreateCache.CacheAlreadyExists):
        _logger.info(f"Cache with name: {cache_name!r} already exists.")
    elif isinstance(create_cache_response, CreateCache.Error):
        _logger.error(f"Error creating cache: {create_cache_response.message}")
    else:
        _logger.error("Unreachable")


def _list_caches(cache_client: SimpleCacheClient) -> None:
    _logger.info("Listing caches:")
    list_caches_response = cache_client.list_caches()
    while True:
        if isinstance(list_caches_response, ListCaches.Success):
            for cache_info in list_caches_response.caches:
                _logger.info(f"- {cache_info.name!r}")
            next_token = list_caches_response.next_token
            if next_token is None:
                break
        elif isinstance(list_caches_response, ListCaches.Error):
            _logger.error(f"Error creating cache: {list_caches_response.message}")
        else:
            _logger.error("Unreachable")

        list_caches_response = cache_client.list_caches(next_token)
    _logger.info("")


if __name__ == "__main__":
    initialize_logging()
    _print_start_banner()
    with SimpleCacheClient(Laptop.latest(), _AUTH_PROVIDER, _ITEM_DEFAULT_TTL_SECONDS) as cache_client:
        _create_cache(cache_client, _CACHE_NAME)
        _list_caches(cache_client)

        _logger.info(f"Setting Key: {_KEY!r} Value: {_VALUE!r}")
        set_response = cache_client.set(_CACHE_NAME, _KEY, _VALUE)
        if isinstance(set_response, CacheSet.Success):
            pass
        elif isinstance(set_response, CacheSet.Error):
            _logger.error(f"Error creating cache: {set_response.message}")
        else:
            _logger.error("Unreachable")

        _logger.info(f"Getting Key: {_KEY!r}")
        get_response = cache_client.get(_CACHE_NAME, _KEY)
        if isinstance(get_response, CacheGet.Hit):
            _logger.info(f"Look up resulted in a hit: {get_response}")
            _logger.info(f"Looked up Value: {get_response.value_string!r}")
        elif isinstance(get_response, CacheGet.Miss):
            _logger.info("Look up resulted in a: miss. This is unexpected.")
        elif isinstance(get_response, CacheGet.Error):
            _logger.error(f"Error creating cache: {get_response.message}")
        else:
            _logger.error("Unreachable")
    _print_end_banner()

Error Handling

Coming Soon!

Tuning

Coming Soon!

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For more info, visit our website at https://gomomento.com!