lightning/pytorch_lightning/utilities/seed.py

69 lines
2.4 KiB
Python

# Copyright The PyTorch Lightning team.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
"""Helper functions to help with reproducibility of models. """
import logging
import os
import random
from typing import Optional
import numpy as np
import torch
from pytorch_lightning.utilities import rank_zero_warn
log = logging.getLogger(__name__)
def seed_everything(seed: Optional[int] = None) -> int:
"""
Function that sets seed for pseudo-random number generators in:
pytorch, numpy, python.random
In addition, sets the env variable `PL_GLOBAL_SEED` which will be passed to
spawned subprocesses (e.g. ddp_spawn backend).
Args:
seed: the integer value seed for global random state in Lightning.
If `None`, will read seed from `PL_GLOBAL_SEED` env variable
or select it randomly.
"""
max_seed_value = np.iinfo(np.uint32).max
min_seed_value = np.iinfo(np.uint32).min
try:
if seed is None:
seed = os.environ.get("PL_GLOBAL_SEED")
seed = int(seed)
except (TypeError, ValueError):
seed = _select_seed_randomly(min_seed_value, max_seed_value)
rank_zero_warn(f"No correct seed found, seed set to {seed}")
if not (min_seed_value <= seed <= max_seed_value):
rank_zero_warn(f"{seed} is not in bounds, numpy accepts from {min_seed_value} to {max_seed_value}")
seed = _select_seed_randomly(min_seed_value, max_seed_value)
# using `log.info` instead of `rank_zero_info`,
# so users can verify the seed is properly set in distributed training.
log.info(f"Global seed set to {seed}")
os.environ["PL_GLOBAL_SEED"] = str(seed)
random.seed(seed)
np.random.seed(seed)
torch.manual_seed(seed)
torch.cuda.manual_seed_all(seed)
return seed
def _select_seed_randomly(min_seed_value: int = 0, max_seed_value: int = 255) -> int:
return random.randint(min_seed_value, max_seed_value)