utils.py

"""
Some useful tools:
  1) set random seeds for everywhere;
  2) a lightweight configuration class inspired by yacs
References:
0) Karpathy's code from https://github.com/karpathy/minGPT
"""

import os
import random
from ast import literal_eval

import numpy as np
import torch

# -----------------------------------------------------------------------------

def set_seed(seed):
    random.seed(seed)
    os.environ['PYTHONHASHSEED'] = str(seed)
    np.random.seed(seed)
    torch.manual_seed(seed)
    torch.cuda.manual_seed(seed)
    torch.cuda.manual_seed_all(seed)
    # Apple Chip
    torch.mps.manual_seed(seed)
    torch.backends.cudnn.deterministic = True
    torch.backends.cudnn.benchmark = False

class ConfigNode:
    """ a lightweight configuration class inspired by yacs """

    def __init__(self, **kwargs):
        self.__dict__.update(kwargs)

    def __str__(self):
        return self._str_helper(0)

    def _str_helper(self, indent):
        """ need to have a helper to support nested indentation for pretty printing """
        parts = []
        for k, v in self.__dict__.items():
            if isinstance(v, ConfigNode):
                parts.append("%s:\n" % k)
                parts.append(v._str_helper(indent + 1))
            else:
                parts.append("%s: %s\n" % (k, v))
        parts = [' ' * (indent * 4) + p for p in parts]
        return "".join(parts)

    def to_dict(self):
        """ return a dict representation of the config """
        return { k: v.to_dict() if isinstance(v, ConfigNode) else v for k, v in self.__dict__.items() }

    def merge_from_dict(self, d):
        self.__dict__.update(d)

    def merge_from_args(self, args):
        """
        update the configuration from a list of strings that is expected
        to come from the command line, i.e. sys.argv[1:].

        The arguments are expected to be in the form of `--arg=value`, and
        the arg can use . to denote nested sub-attributes. Example:

        --model.n_layer=10 --trainer.batch_size=32
        """
        for arg in args:

            keyval = arg.split('=')
            assert len(keyval) == 2, "expecting each override arg to be of form --arg=value, got %s" % arg
            key, val = keyval # unpack

            # first translate val into a python object
            try:
                val = literal_eval(val)
                """
                need some explanation here.
                - if val is simply a string, literal_eval will throw a ValueError
                - if val represents a thing (like an 3, 3.14, [1,2,3], False, None, etc.) it will get created
                """
            except ValueError:
                pass

            # find the appropriate object to insert the attribute into
            assert key[:2] == '--'
            key = key[2:] # strip the '--'
            keys = key.split('.')
            obj = self
            for k in keys[:-1]:
                obj = getattr(obj, k)
            leaf_key = keys[-1]

            # ensure that this attribute exists
            assert hasattr(obj, leaf_key), f"{key} is not an attribute that exists in the config"

            # overwrite the attribute
            print("command line overwriting config attribute %s with %s" % (key, val))
            setattr(obj, leaf_key, val)