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Method Stacking

About

Complex fine-tuning often requires hybrid approaches.

The d9d.peft.all package facilitates this by grouping multiple PEFT configurations into a single PeftStack.

Usage Example

Applying LoRA to attention layers while fully fine-tuning normalization layers.

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import re
from d9d.peft.all import PeftStackConfig, peft_method_from_config
from d9d.peft.lora import LoRAConfig, LoRAParameters
from d9d.peft.full_tune import FullTuneConfig
from d9d.peft import inject_peft_and_freeze, merge_peft

# 1. Define your Strategy
config = PeftStackConfig(
    methods=[
        # Method A: LoRA on attention projections
        LoRAConfig(
            module_name_pattern=re.compile(r".*attention\..*_proj.*"),
            params=LoRAParameters(r=8, alpha=16, dropout=0.05)
        ),
        # Method B: Full Tune on LayerNorms
        FullTuneConfig(
            module_name_pattern=re.compile(r".*norm.*")
        )
    ]
)

# 2. Create Factory
# This automatically creates a PeftStack containing the sub-methods
method = peft_method_from_config(config)

# 3. Inject
mapper = inject_peft_and_freeze(method, model)

# ... pass 'mapper' object to d9d's Trainer or manually load a model checkpoint ...

# ... train a model ...

# 4. Merge - for exporting a model
merge_peft(method, model)

d9d.peft.all

Package for composing multiple PEFT methods into a stack.

PeftStack

Bases: PeftMethod[PeftStackConfig]

A composite PEFT method that applies a list of methods sequentially.

__init__(methods)

Constructs a PeftStack object.

Parameters:

Name Type Description Default
methods list[PeftMethod]

A list of instantiated PEFT methods to apply in order.

 required

PeftStackConfig

Bases: BaseModel

Configuration for applying a stack of multiple PEFT methods sequentially.

Attributes:

Name Type Description
kind Literal['stack']

Discriminator field, always "stack".
methods list[AnyPeftConfig]

A list of specific PEFT configurations (e.g., LoRA, FullTune) to apply in order.

peft_method_from_config(config)

Factory function to instantiate the correct PeftMethod based on the configuration type.

Parameters:

Name Type Description Default
config TConfig

A specific PEFT configuration object (e.g., LoRAConfig).

 required

Returns:

Type Description
PeftMethod[TConfig]

The corresponding method instance.