Create a astroid.constants.py to avoid circular imports

And add PY3X type constants in it.

14 files changed, 24 insertions, 40 deletions

diff --git a/astroid/_ast.py b/astroid/_ast.py
index 8d9a8d23..8bafa799 100644
--- a/astroid/_ast.py
+++ b/astroid/_ast.py
@@ -5,6 +5,7 @@ from functools import partial
 from typing import Optional
 
 import astroid
+from astroid.constants import PY38
 
 try:
     import typed_ast.ast3 as _ast_py3
@@ -12,7 +13,6 @@ except ImportError:
     _ast_py3 = None
 
 
-PY38 = sys.version_info[:2] >= (3, 8)
 if PY38:
     # On Python 3.8, typed_ast was merged back into `ast`
     _ast_py3 = ast
diff --git a/astroid/bases.py b/astroid/bases.py
index 33ffd5fc..b4c16678 100644
--- a/astroid/bases.py
+++ b/astroid/bases.py
@@ -25,10 +25,10 @@ inference utils.
 
 import builtins
 import collections
-import sys
 
 from astroid import context as contextmod
 from astroid import util
+from astroid.constants import PY310
 from astroid.exceptions import (
     AstroidTypeError,
     AttributeInferenceError,
@@ -42,7 +42,6 @@ BUILTINS = builtins.__name__
 manager = util.lazy_import("manager")
 MANAGER = manager.AstroidManager()
 
-PY310 = sys.version_info >= (3, 10)
 
 # TODO: check if needs special treatment
 BUILTINS = "builtins"
diff --git a/astroid/brain/brain_collections.py b/astroid/brain/brain_collections.py
index cb3d4c20..1397f1ea 100644
--- a/astroid/brain/brain_collections.py
+++ b/astroid/brain/brain_collections.py
@@ -8,11 +8,9 @@
 
 # Licensed under the LGPL: https://www.gnu.org/licenses/old-licenses/lgpl-2.1.en.html
 # For details: https://github.com/PyCQA/astroid/blob/master/LICENSE
-import sys
 
 import astroid
-
-PY39 = sys.version_info >= (3, 9)
+from astroid.constants import PY39
 
 
 def _collections_transform():
diff --git a/astroid/brain/brain_crypt.py b/astroid/brain/brain_crypt.py
index 076c1927..b5a1cede 100644
--- a/astroid/brain/brain_crypt.py
+++ b/astroid/brain/brain_crypt.py
@@ -1,10 +1,8 @@
 # Licensed under the LGPL: https://www.gnu.org/licenses/old-licenses/lgpl-2.1.en.html
 # For details: https://github.com/PyCQA/astroid/blob/master/LICENSE
-import sys
 
 import astroid
-
-PY37 = sys.version_info >= (3, 7)
+from astroid.constants import PY37
 
 if PY37:
     # Since Python 3.7 Hashing Methods are added
diff --git a/astroid/brain/brain_fstrings.py b/astroid/brain/brain_fstrings.py
index db0c9edb..bd98a8ba 100644
--- a/astroid/brain/brain_fstrings.py
+++ b/astroid/brain/brain_fstrings.py
@@ -6,9 +6,9 @@
 # Licensed under the LGPL: https://www.gnu.org/licenses/old-licenses/lgpl-2.1.en.html
 # For details: https://github.com/PyCQA/astroid/blob/master/LICENSE
 import collections.abc
-import sys
 
 import astroid
+from astroid.constants import PY36
 
 
 def _clone_node_with_lineno(node, parent, lineno):
@@ -44,7 +44,7 @@ def _transform_formatted_value(node):  # pylint: disable=inconsistent-return-sta
             return new_node
 
 
-if sys.version_info[:2] >= (3, 6):
+if PY36:
     # TODO: this fix tries to *patch* http://bugs.python.org/issue29051
     # The problem is that FormattedValue.value, which is a Name node,
     # has wrong line numbers, usually 1. This creates problems for pylint,
diff --git a/astroid/brain/brain_hashlib.py b/astroid/brain/brain_hashlib.py
index 90ba48eb..f7524847 100644
--- a/astroid/brain/brain_hashlib.py
+++ b/astroid/brain/brain_hashlib.py
@@ -8,11 +8,9 @@
 
 # Licensed under the LGPL: https://www.gnu.org/licenses/old-licenses/lgpl-2.1.en.html
 # For details: https://github.com/PyCQA/astroid/blob/master/LICENSE
-import sys
 
 import astroid
-
-PY36 = sys.version_info >= (3, 6)
+from astroid.constants import PY36
 
 
 def _hashlib_transform():
diff --git a/astroid/brain/brain_re.py b/astroid/brain/brain_re.py
index 544191b6..46acf5ca 100644
--- a/astroid/brain/brain_re.py
+++ b/astroid/brain/brain_re.py
@@ -1,13 +1,9 @@
 # Licensed under the LGPL: https://www.gnu.org/licenses/old-licenses/lgpl-2.1.en.html
 # For details: https://github.com/PyCQA/astroid/blob/master/LICENSE
-import sys
 
 import astroid
 from astroid import MANAGER, context, inference_tip, nodes
-
-PY36 = sys.version_info >= (3, 6)
-PY37 = sys.version_info[:2] >= (3, 7)
-PY39 = sys.version_info[:2] >= (3, 9)
+from astroid.constants import PY36, PY37, PY39
 
 if PY36:
     # Since Python 3.6 there is the RegexFlag enum
diff --git a/astroid/brain/brain_subprocess.py b/astroid/brain/brain_subprocess.py
index cef1deb8..d56cb166 100644
--- a/astroid/brain/brain_subprocess.py
+++ b/astroid/brain/brain_subprocess.py
@@ -11,14 +11,10 @@
 # Licensed under the LGPL: https://www.gnu.org/licenses/old-licenses/lgpl-2.1.en.html
 # For details: https://github.com/PyCQA/astroid/blob/master/LICENSE
 
-import sys
 import textwrap
 
 import astroid
-
-PY39 = sys.version_info >= (3, 9)
-PY37 = sys.version_info >= (3, 7)
-PY36 = sys.version_info >= (3, 6)
+from astroid.constants import PY36, PY37, PY39
 
 
 def _subprocess_transform():
diff --git a/astroid/brain/brain_type.py b/astroid/brain/brain_type.py
index c7164704..2b340015 100644
--- a/astroid/brain/brain_type.py
+++ b/astroid/brain/brain_type.py
@@ -15,13 +15,11 @@ Doing this type[int] is allowed whereas str[int] is not.
 
 Thanks to Lukasz Langa for fruitful discussion.
 """
-import sys
 
 from astroid import MANAGER, extract_node, inference_tip, nodes
+from astroid.constants import PY39
 from astroid.exceptions import UseInferenceDefault
 
-PY39 = sys.version_info >= (3, 9)
-
 
 def _looks_like_type_subscript(node):
     """
diff --git a/astroid/brain/brain_typing.py b/astroid/brain/brain_typing.py
index 38ec26d2..18f7e637 100644
--- a/astroid/brain/brain_typing.py
+++ b/astroid/brain/brain_typing.py
@@ -10,21 +10,18 @@
 # Copyright (c) 2021 hippo91 <guillaume.peillex@gmail.com>
 
 """Astroid hooks for typing.py support."""
-import sys
 import typing
 from functools import partial
 
 import astroid
 from astroid import MANAGER, context, extract_node, inference_tip, node_classes, nodes
+from astroid.constants import PY37, PY39
 from astroid.exceptions import (
     AttributeInferenceError,
     InferenceError,
     UseInferenceDefault,
 )
 
-PY37 = sys.version_info[:2] >= (3, 7)
-PY39 = sys.version_info[:2] >= (3, 9)
-
 TYPING_NAMEDTUPLE_BASENAMES = {"NamedTuple", "typing.NamedTuple"}
 TYPING_TYPEVARS = {"TypeVar", "NewType"}
 TYPING_TYPEVARS_QUALIFIED = {"typing.TypeVar", "typing.NewType"}
diff --git a/astroid/constants.py b/astroid/constants.py
new file mode 100644
index 00000000..f9110dbd
--- /dev/null
+++ b/astroid/constants.py
@@ -0,0 +1,7 @@
+import sys
+
+PY36 = sys.version_info >= (3, 6)
+PY37 = sys.version_info >= (3, 7)
+PY38 = sys.version_info >= (3, 8)
+PY39 = sys.version_info >= (3, 9)
+PY310 = sys.version_info >= (3, 10)
diff --git a/astroid/rebuilder.py b/astroid/rebuilder.py
index d97c81b5..d71f69b9 100644
--- a/astroid/rebuilder.py
+++ b/astroid/rebuilder.py
@@ -29,7 +29,6 @@
 order to get a single Astroid representation
 """
 
-import sys
 from typing import (
     TYPE_CHECKING,
     Callable,
@@ -45,6 +44,8 @@ from typing import (
     overload,
 )
 
+from astroid.constants import PY37, PY38, PY39
+
 try:
     from typing import Final
 except ImportError:
@@ -70,9 +71,7 @@ REDIRECT: Final[Dict[str, str]] = {
     "keyword": "Keyword",
     "match_case": "MatchCase",
 }
-PY37 = sys.version_info >= (3, 7)
-PY38 = sys.version_info >= (3, 8)
-PY39 = sys.version_info >= (3, 9)
+
 
 T_Doc = TypeVar(
     "T_Doc",
diff --git a/astroid/scoped_nodes.py b/astroid/scoped_nodes.py
index bb124d40..c3603c63 100644
--- a/astroid/scoped_nodes.py
+++ b/astroid/scoped_nodes.py
@@ -41,13 +41,13 @@ Lambda, GeneratorExp, DictComp and SetComp to some extent).
 import builtins
 import io
 import itertools
-import sys
 from typing import List, Optional
 
 from astroid import bases
 from astroid import context as contextmod
 from astroid import decorators as decorators_mod
 from astroid import manager, mixins, node_classes, util
+from astroid.constants import PY36, PY39
 from astroid.exceptions import (
     AstroidBuildingError,
     AstroidTypeError,
@@ -60,8 +60,6 @@ from astroid.exceptions import (
 )
 from astroid.interpreter import dunder_lookup, objectmodel
 
-PY39 = sys.version_info[:2] >= (3, 9)
-
 BUILTINS = builtins.__name__
 ITER_METHODS = ("__iter__", "__getitem__")
 EXCEPTION_BASE_CLASSES = frozenset({"Exception", "BaseException"})
@@ -1516,7 +1514,7 @@ class FunctionDef(mixins.MultiLineBlockMixin, node_classes.Statement, Lambda):
         if isinstance(frame, ClassDef):
             if self.name == "__new__":
                 return "classmethod"
-            if sys.version_info >= (3, 6) and self.name == "__init_subclass__":
+            if PY36 and self.name == "__init_subclass__":
                 return "classmethod"
 
             type_name = "method"
diff --git a/astroid/test_utils.py b/astroid/test_utils.py
index 2ff6eef9..974869eb 100644
--- a/astroid/test_utils.py
+++ b/astroid/test_utils.py
@@ -39,7 +39,7 @@ def require_version(minver=None, maxver=None):
             ) from exc
 
     def check_require_version(f):
-        current = sys.version_info[:3]
+        current = sys.version_info[:3]  # TODO
         if parse(minver, "0") < current <= parse(maxver, "4"):
             return f