Move PYPY into compat.

Author: domdfcoding

domdf_python_tools/compat.py

@@ -40,13 +40,14 @@
 #
 
 # stdlib
+import platform
 import sys
 from typing import TYPE_CHECKING, ContextManager, Optional, TypeVar
 
 # this package
 import domdf_python_tools
 
-__all__ = ["importlib_resources", "importlib_metadata", "nullcontext"]
+__all__ = ["importlib_resources", "importlib_metadata", "nullcontext", "PYPY"]
 
 if sys.version_info < (3, 7):  # pragma: no cover (>=py37)
 	# 3rd party
@@ -103,3 +104,10 @@ def __exit__(self, *excinfo):
 else:  # pragma: no cover (<py37)
 	# stdlib
 	from contextlib import nullcontext
+
+PYPY = platform.python_implementation() == "PyPy"
+"""
+:py:obj:`True` if running on PyPy rather than CPython.
+
+.. versionadded:: 2.3.0
+"""

domdf_python_tools/doctools.py

@@ -28,12 +28,12 @@
 
 # stdlib
 import builtins
-import platform
 from inspect import cleandoc
 from types import MethodType
 from typing import Any, Callable, Dict, Optional, Sequence, Type, TypeVar, Union
 
 # this package
+from domdf_python_tools.compat import PYPY
 from domdf_python_tools.typing import MethodDescriptorType, MethodWrapperType, WrapperDescriptorType
 
 __all__ = [
@@ -49,7 +49,6 @@
 		]
 
 F = TypeVar('F', bound=Callable[..., Any])
-PYPY = platform.python_implementation() == "PyPy"
 
 
 def deindent_string(string: Optional[str]) -> str:

domdf_python_tools/testing/selectors.py

@@ -38,7 +38,7 @@
 from _pytest.mark import MarkDecorator  # nodep
 
 # this package
-from domdf_python_tools.doctools import PYPY
+from domdf_python_tools.compat import PYPY
 from domdf_python_tools.testing.utils import is_docker
 from domdf_python_tools.versions import Version