Merge Strategies

Advanced merging strategies for Confii.

This module provides different merge strategies for combining configurations, allowing fine-grained control over how values are merged.

class confii.merge_strategies.AdvancedConfigMerger(default_strategy: MergeStrategy = MergeStrategy.MERGE)

Bases: object

Advanced configuration merger with strategy support.

This class provides configurable merge strategies for combining configurations with fine-grained control over merge behavior.

__init__(default_strategy: MergeStrategy = MergeStrategy.MERGE) → None

Initialize the advanced config merger.

Parameters:

default_strategy – Default merge strategy to use

merge(base: Dict[str, Any], new: Dict[str, Any], path: str = '') → Dict[str, Any]

Merge two configurations using configured strategies.

Parameters:

• base – Base configuration dictionary

• new – New configuration dictionary to merge in

• path – Current path prefix (for strategy lookup)

Returns:

Merged configuration dictionary

Example

>>> merger = AdvancedConfigMerger()
>>> base = {"database": {"host": "localhost"}, "app": {"debug": True}}
>>> new = {"database": {"port": 5432}}
>>> result = merger.merge(base, new)
>>> # Result: {"database": {"host": "localhost", "port": 5432}, "app": {"debug": True}}

set_strategy(key_path: str, strategy: MergeStrategy) → None

Set merge strategy for a specific key path.

Parameters:

• key_path – Dot-separated key path (e.g., “database”, “app.debug”)

• strategy – Merge strategy to use for this key

Example

>>> merger = AdvancedConfigMerger()
>>> merger.set_strategy("database", MergeStrategy.REPLACE)
>>> merger.set_strategy("app.debug", MergeStrategy.REPLACE)

class confii.merge_strategies.MergeStrategy(*values)

Bases: Enum

Merge strategies for configuration values.

This enum defines the available strategies for merging configuration values when combining configurations from multiple sources.

REPLACE

Replace the base value entirely with the new value. Use this when you want new values to completely override existing ones.

MERGE

Deep merge nested dictionaries while preserving existing values. Use this for nested configurations where you want to combine values.

APPEND

Append new list items to the end of existing lists. Use this when you want to combine list values.

PREPEND

Prepend new list items to the beginning of existing lists. Use this when new list items should have priority.

INTERSECTION

Keep only keys that exist in both configurations. Use this to create a configuration with only common settings.

UNION

Keep all keys from both configurations, merging values for common keys. Use this to combine all available configuration options.

Example

>>> from confii.merge_strategies import (
...     MergeStrategy,
...     AdvancedConfigMerger,
... )
>>> merger = AdvancedConfigMerger(MergeStrategy.MERGE)
>>> merger.set_strategy("database", MergeStrategy.REPLACE)
>>> result = merger.merge(base_config, override_config)