DeepLearningExamples/PyTorch/Classification/ConvNets/image_classification/models/model.py

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2021-04-09 23:12:57 +02:00
from dataclasses import dataclass, asdict, replace
from typing import Optional, Callable
import os
import torch
import argparse
@dataclass
class ModelArch:
pass
@dataclass
class ModelParams:
def parser(self, name):
return argparse.ArgumentParser(description=f"{name} arguments", add_help = False, usage="")
@dataclass
class OptimizerParams:
pass
@dataclass
class Model:
constructor: Callable
arch: ModelArch
params: Optional[ModelParams]
optimizer_params: Optional[OptimizerParams] = None
checkpoint_url: Optional[str] = None
class EntryPoint:
def __init__(self, name: str, model: Model):
self.name = name
self.model = model
def __call__(self, pretrained=False, pretrained_from_file=None, **kwargs):
assert not (pretrained and (pretrained_from_file is not None))
params = replace(self.model.params, **kwargs)
model = self.model.constructor(arch=self.model.arch, **asdict(params))
state_dict = None
if pretrained:
assert self.model.checkpoint_url is not None
state_dict = torch.hub.load_state_dict_from_url(self.model.checkpoint_url, map_location=torch.device('cpu'))
if pretrained_from_file is not None:
if os.path.isfile(pretrained_from_file):
print(
"=> loading pretrained weights from '{}'".format(
pretrained_from_file
)
)
state_dict = torch.load(pretrained_from_file, map_location=torch.device('cpu'))
else:
print(
"=> no pretrained weights found at '{}'".format(
pretrained_from_file
)
)
# Temporary fix to allow NGC checkpoint loading
if state_dict is not None:
state_dict = {
k[len("module."):] if k.startswith("module.") else k: v for k, v in state_dict.items()
}
model.load_state_dict(state_dict)
return model
def parser(self):
if self.model.params is None: return None
parser = self.model.params.parser(self.name)
parser.add_argument(
"--pretrained-from-file",
default=None,
type=str,
metavar="PATH",
help="load weights from local file",
)
if self.model.checkpoint_url is not None:
parser.add_argument(
"--pretrained",
default=False,
action="store_true",
help="load pretrained weights from NGC"
)
return parser
def create_entrypoint(m: Model):
def _ep(**kwargs):
params = replace(m.params, **kwargs)
return m.constructor(arch=m.arch, **asdict(params))
return _ep