fastcfg package

Subpackages

• fastcfg.backoff package
  • Submodules
  • fastcfg.backoff.policies module
    • BASIC_BACKOFF_POLICY
  • Module contents
    • BackoffPolicy
      • BackoffPolicy.max_retries
      • BackoffPolicy.base_delay
      • BackoffPolicy.max_delay
      • BackoffPolicy.factor
      • BackoffPolicy.jitter
      • BackoffPolicy.base_delay
      • BackoffPolicy.factor
      • BackoffPolicy.jitter
      • BackoffPolicy.max_delay
      • BackoffPolicy.max_retries
    • exponential_backoff()
• fastcfg.cache package
  • Submodules
  • fastcfg.cache.policies module
    • TEN_MIN_TTL
    • ONE_HOUR_TTL
    • DAILY_TTL
    • LRU_POLICY
    • MRU_POLICY
  • fastcfg.cache.store module
    • CacheStore
      • CacheStore._caches
      • CacheStore.add_cache()
      • CacheStore.clear_all_caches()
      • CacheStore.clear_cache()
      • CacheStore.get_cache()
      • CacheStore.add_cache()
      • CacheStore.clear_all_caches()
      • CacheStore.clear_cache()
      • CacheStore.get_cache()
  • fastcfg.cache.strategies module
    • LRUCacheStrategy
      • LRUCacheStrategy.on_access()
      • LRUCacheStrategy.on_insertion()
    • MRUCacheStrategy
      • MRUCacheStrategy.on_access()
      • MRUCacheStrategy.on_insertion()
    • TTLCacheStrategy
      • TTLCacheStrategy._seconds
      • TTLCacheStrategy.is_valid()
      • TTLCacheStrategy.on_insertion()
      • TTLCacheStrategy.on_invalidation()
  • Module contents
    • AbstractCacheStrategy
      • AbstractCacheStrategy.is_valid()
      • AbstractCacheStrategy.on_access()
      • AbstractCacheStrategy.on_insertion()
      • AbstractCacheStrategy.on_invalidation()
    • AbstractUsageCacheStrategy
      • AbstractUsageCacheStrategy.is_valid()
      • AbstractUsageCacheStrategy.on_access()
      • AbstractUsageCacheStrategy.on_insertion()
      • AbstractUsageCacheStrategy.on_invalidation()
    • Cache
      • Cache.get_metadata()
      • Cache.get_value()
      • Cache.is_valid()
      • Cache.set_value()
• fastcfg.config package
  • Submodules
  • fastcfg.config.attributes module
    • ConfigAttributes
      • ConfigAttributes.__attributes
      • ConfigAttributes.__init__()
      • ConfigAttributes.get_attribute()
      • ConfigAttributes.get_attributes()
      • ConfigAttributes._convert_value_to_item()
      • ConfigAttributes._add_attribute()
      • ConfigAttributes.add_or_update_attribute()
      • ConfigAttributes.add_or_update_attribute()
      • ConfigAttributes.get_attribute()
      • ConfigAttributes.get_attributes()
      • ConfigAttributes.has_attribute()
      • ConfigAttributes.remove_attribute()
  • fastcfg.config.interface module
    • ConfigInterface
      • ConfigInterface._config_attributes
      • ConfigInterface._current_env
      • ConfigInterface.__init__()
      • ConfigInterface.set_environment()
      • ConfigInterface.get_environment()
      • ConfigInterface.to_dict()
      • ConfigInterface.value()
      • ConfigInterface.environment
      • ConfigInterface.environments
      • ConfigInterface.export_values()
      • ConfigInterface.get()
      • ConfigInterface.import_values()
      • ConfigInterface.items()
      • ConfigInterface.keys()
      • ConfigInterface.load()
      • ConfigInterface.pop()
      • ConfigInterface.remove_environment()
      • ConfigInterface.save()
      • ConfigInterface.set_environment()
      • ConfigInterface.set_parent()
      • ConfigInterface.to_dict()
      • ConfigInterface.update()
      • ConfigInterface.value
      • ConfigInterface.values()
  • fastcfg.config.items module
    • AbstractConfigItem
      • AbstractConfigItem._wrapped_dict_items
      • AbstractConfigItem.__init__()
      • AbstractConfigItem.value()
      • AbstractConfigItem._get_value()
      • AbstractConfigItem._set_value()
      • AbstractConfigItem.__getattr__()
      • AbstractConfigItem.as_callable()
      • AbstractConfigItem.set_parent()
      • AbstractConfigItem.value
    • BuiltInConfigItem
      • BuiltInConfigItem._value
      • BuiltInConfigItem._get_value()
    • LiveConfigItem
      • LiveConfigItem._state_tracker
      • LiveConfigItem.__init__()
      • LiveConfigItem._get_value()
      • LiveConfigItem.value()
      • LiveConfigItem.as_callable()
      • LiveConfigItem.value
  • fastcfg.config.state module
    • AbstractLiveStateTracker
      • AbstractLiveStateTracker._cache_uuid_key
      • AbstractLiveStateTracker.__init__()
      • AbstractLiveStateTracker.get_state()
      • AbstractLiveStateTracker.get_state()
    • AbstractStateTracker
      • AbstractStateTracker.get_state()
      • AbstractStateTracker.get_state_value()
      • AbstractStateTracker.get_state()
      • AbstractStateTracker.get_state_value()
    • CacheMixin
    • RetriableMixin
      • RetriableMixin._retry
      • RetriableMixin._backoff_policy
      • RetriableMixin._call_retriable_function()
  • fastcfg.config.utils module
    • create_config_dict()
    • deep_merge_config()
    • potentially_has_children()
    • resolve_all_values()
  • fastcfg.config.value_wrapper module
    • OperatorsMixin
    • ValueWrapper
      • ValueWrapper.factory()
      • ValueWrapper.unwrap()
  • Module contents
• fastcfg.default package
  • Module contents
    • defaults
• fastcfg.sources package
  • Subpackages
    • fastcfg.sources.aws package
      • Submodules
      • fastcfg.sources.aws.aws_config_tracker module
      • fastcfg.sources.aws.lambda module
      • Module contents
    • fastcfg.sources.files package
      • Submodules
      • fastcfg.sources.files.file_state_tracker module
      • fastcfg.sources.files.ini module
      • fastcfg.sources.files.json module
      • fastcfg.sources.files.yaml module
      • Module contents
    • fastcfg.sources.memory package
      • Submodules
      • fastcfg.sources.memory.callable module
      • fastcfg.sources.memory.environment module
      • Module contents
    • fastcfg.sources.remote package
      • Submodules
      • fastcfg.sources.remote.network module
      • Module contents
  • Module contents
• fastcfg.validation package
  • Submodules
  • fastcfg.validation.policies module
    • LengthValidator
      • LengthValidator.error_message()
      • LengthValidator.validate()
    • PydanticValidator
      • PydanticValidator.error_message()
      • PydanticValidator.validate()
    • RangeValidator
      • RangeValidator.error_message()
      • RangeValidator.validate()
    • RegexValidator
      • RegexValidator.error_message()
      • RegexValidator.validate()
    • TypeValidator
      • TypeValidator.error_message()
      • TypeValidator.validate()
    • URLValidator
      • URLValidator.error_message()
  • fastcfg.validation.validatable module
    • ValidatableMixin
      • ValidatableMixin.add_validator()
      • ValidatableMixin.get_validators()
      • ValidatableMixin.validate()
      • ValidatableMixin.value
    • md5_hash_state()
  • Module contents
    • IConfigValidator
      • IConfigValidator.error_message()
      • IConfigValidator.validate()

Submodules

fastcfg.exceptions module

exception fastcfg.exceptions.ConfigItemValidationError(message: str)

Bases: Exception

Exception raised when a config item value fails validation.

exception fastcfg.exceptions.FileReadError

Bases: Exception

Exception raised when a file cannot be read.

exception fastcfg.exceptions.InvalidOperationError(message: str = 'Invalid operation performed.')

Bases: Exception

Exception raised when an invalid operation is performed.

exception fastcfg.exceptions.MaxRetriesExceededError(backoff_policy, total_time_slept: float)

Bases: Exception

Exception raised when the maximum number of retries is exceeded in exponential backoff.

exception fastcfg.exceptions.MissingCacheKeyError(key)

Bases: Exception

Exception raised when a cache key doesn’t exist.

exception fastcfg.exceptions.MissingConfigKeyError(key)

Bases: Exception

Exception raised when a config key doesn’t exist.

exception fastcfg.exceptions.MissingDependencyError(dependency: str)

Bases: Exception

Exception raised when a dependency is missing.

exception fastcfg.exceptions.MissingEnvironmentVariableError(key)

Bases: Exception

Exception raised when an environment variable doesn’t exist.

exception fastcfg.exceptions.NetworkError

Bases: Exception

Exception raised when a config key doesn’t exist.

Module contents

FastCFG - Modern configuration management for Python applications.

Created by Josh Breidinger (2025) Author: Josh Breidinger Email: company@breisoft.com GitHub: https://github.com/breisoft

Born from the frustration of serverless configuration hell, FastCFG makes config management simple, fast, and reliable.

fastcfg.needs_value(func: Callable[[...], Any], config_value: Any, *args: Any, verbose: bool = False, **kwargs: Any) → bool | None

Test whether a function requires explicit .value access or works with FastCFG magic.

This helper function determines if you can pass a FastCFG config value directly to a function, or if you need to use .value to extract the underlying value. This is particularly useful for identifying C extensions that require exact types.

Parameters:

• func – The function to test compatibility with

• config_value – A FastCFG wrapped value (e.g., config.port)

• *args – Additional positional arguments to pass to func (after config_value)

• verbose – If True, prints diagnostic information about the test

• **kwargs – Keyword arguments to pass to func

Returns:

• False: Function works with FastCFG magic (no .value needed)

• True: Function requires .value to be called on config_value

• None: Function doesn’t work even with .value (incompatible)

Return type:

bool or None

Example

config.size = 10

# Check if np.zeros needs .value if needs_value(np.zeros, config.size):

arr = np.zeros(config.size.value)

else:

arr = np.zeros(config.size)

# With verbose output for debugging needs_value(np.zeros, config.size, verbose=True) # Prints: zeros requires .value - use config.size.value

fastcfg.refresh(target: Config | AbstractConfigItem)

Manually refresh a Config or ConfigItem to detect external changes.

Parameters:

target – Config object or ConfigItem to refresh

Example

# In your own loop for _ in range(60):

refresh(config.my_var) # Triggers change detection time.sleep(1)