Source code for libai.config.instantiate

# coding=utf-8
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#     http://www.apache.org/licenses/LICENSE-2.0
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import dataclasses
import logging
from collections import abc
from typing import Any

from libai.config.lazy import _convert_target_to_string, locate

__all__ = ["dump_dataclass", "instantiate"]


def dump_dataclass(obj: Any):
    """
    Dump a dataclass recursively into a dict that can be later instantiated.

    Args:
        obj: a dataclass object

    Returns:
        dict
    """
    assert dataclasses.is_dataclass(obj) and not isinstance(
        obj, type
    ), "dump_dataclass() requires an instance of a dataclass."
    ret = {"_target_": _convert_target_to_string(type(obj))}
    for f in dataclasses.fields(obj):
        v = getattr(obj, f.name)
        if dataclasses.is_dataclass(v):
            v = dump_dataclass(v)
        if isinstance(v, (list, tuple)):
            v = [dump_dataclass(x) if dataclasses.is_dataclass(x) else x for x in v]
        ret[f.name] = v
    return ret


[docs]def instantiate(cfg): """ Recursively instantiate objects defined in dictionaries by "_target_" and arguments. Args: cfg: a dict-like object with "_target_" that defines the caller, and other keys that define the arguments Returns: object instantiated by cfg """ from omegaconf import ListConfig if isinstance(cfg, ListConfig): lst = [instantiate(x) for x in cfg] return ListConfig(lst, flags={"allow_objects": True}) if isinstance(cfg, list): # Specialize for list, because many classes take # list[objects] as arguments, such as ResNet, DatasetMapper return [instantiate(x) for x in cfg] if isinstance(cfg, abc.Mapping) and "_target_" in cfg: # conceptually equivalent to hydra.utils.instantiate(cfg) with _convert_=all, # but faster: https://github.com/facebookresearch/hydra/issues/1200 cfg = {k: instantiate(v) for k, v in cfg.items()} cls = cfg.pop("_target_") cls = instantiate(cls) if isinstance(cls, str): cls_name = cls cls = locate(cls_name) assert cls is not None, cls_name else: try: cls_name = cls.__module__ + "." + cls.__qualname__ except Exception: # target could be anything, so the above could fail cls_name = str(cls) assert callable(cls), f"_target_ {cls} does not define a callable object" try: return cls(**cfg) except TypeError: logger = logging.getLogger(__name__) logger.error(f"Error when instantiating {cls_name}!") raise return cfg # return as-is if don't know what to do