From 3cf3998ea5e8550597ce0cb122482e22bcbb88a2 Mon Sep 17 00:00:00 2001
From: Jeremy Reizenstein <reizenstein@meta.com>
Date: Thu, 12 Jan 2023 14:25:40 -0800
Subject: [PATCH] assume Python 3.8+

Summary: Remove workarounds for Python 3.7

Reviewed By: davidsonic

Differential Revision: D42451534

fbshipit-source-id: 461dd311f3bccf7bef120ffe0b97fbbd173d95be
---
 pytorch3d/common/datatypes.py          | 16 ----------------
 pytorch3d/implicitron/dataset/types.py | 15 +++++++++++++--
 pytorch3d/implicitron/tools/config.py  | 15 +++++++++++++--
 pytorch3d/io/utils.py                  | 12 ++----------
 4 files changed, 28 insertions(+), 30 deletions(-)

diff --git a/pytorch3d/common/datatypes.py b/pytorch3d/common/datatypes.py
index 8810d816..0c14ed10 100644
--- a/pytorch3d/common/datatypes.py
+++ b/pytorch3d/common/datatypes.py
@@ -57,19 +57,3 @@ def get_device(x, device: Optional[Device] = None) -> torch.device:
 
     # Default device is cpu
     return torch.device("cpu")
-
-
-# Provide get_origin and get_args even in Python 3.7.
-
-if sys.version_info >= (3, 8, 0):
-    from typing import get_args, get_origin
-elif sys.version_info >= (3, 7, 0):
-
-    def get_origin(cls):  # pragma: no cover
-        return getattr(cls, "__origin__", None)
-
-    def get_args(cls):  # pragma: no cover
-        return getattr(cls, "__args__", None)
-
-else:
-    raise ImportError("This module requires Python 3.7+")
diff --git a/pytorch3d/implicitron/dataset/types.py b/pytorch3d/implicitron/dataset/types.py
index be67c055..174f9f5d 100644
--- a/pytorch3d/implicitron/dataset/types.py
+++ b/pytorch3d/implicitron/dataset/types.py
@@ -9,10 +9,21 @@ import dataclasses
 import gzip
 import json
 from dataclasses import dataclass, Field, MISSING
-from typing import Any, cast, Dict, IO, Optional, Tuple, Type, TypeVar, Union
+from typing import (
+    Any,
+    cast,
+    Dict,
+    get_args,
+    get_origin,
+    IO,
+    Optional,
+    Tuple,
+    Type,
+    TypeVar,
+    Union,
+)
 
 import numpy as np
-from pytorch3d.common.datatypes import get_args, get_origin
 
 
 _X = TypeVar("_X")
diff --git a/pytorch3d/implicitron/tools/config.py b/pytorch3d/implicitron/tools/config.py
index 6a64dbaa..5e5d945c 100644
--- a/pytorch3d/implicitron/tools/config.py
+++ b/pytorch3d/implicitron/tools/config.py
@@ -12,10 +12,21 @@ import warnings
 from collections import Counter, defaultdict
 from enum import Enum
 from functools import partial
-from typing import Any, Callable, Dict, List, Optional, Tuple, Type, TypeVar, Union
+from typing import (
+    Any,
+    Callable,
+    Dict,
+    get_args,
+    get_origin,
+    List,
+    Optional,
+    Tuple,
+    Type,
+    TypeVar,
+    Union,
+)
 
 from omegaconf import DictConfig, OmegaConf, open_dict
-from pytorch3d.common.datatypes import get_args, get_origin
 
 
 """
diff --git a/pytorch3d/io/utils.py b/pytorch3d/io/utils.py
index fd60ee9b..76772405 100644
--- a/pytorch3d/io/utils.py
+++ b/pytorch3d/io/utils.py
@@ -7,7 +7,7 @@
 import contextlib
 import pathlib
 import warnings
-from typing import ContextManager, IO, Optional, Union
+from typing import cast, ContextManager, IO, Optional, Union
 
 import numpy as np
 import torch
@@ -17,14 +17,6 @@ from PIL import Image
 from ..common.datatypes import Device
 
 
-@contextlib.contextmanager
-def nullcontext(x):
-    """
-    This is just like contextlib.nullcontext but also works in Python 3.6.
-    """
-    yield x
-
-
 PathOrStr = Union[pathlib.Path, str]
 
 
@@ -36,7 +28,7 @@ def _open_file(f, path_manager: PathManager, mode: str = "r") -> ContextManager[
         f = f.open(mode)
         return contextlib.closing(f)
     else:
-        return nullcontext(f)
+        return contextlib.nullcontext(cast(IO, f))
 
 
 def _make_tensor(