bpo-38659: [Enum] add _simple_enum decorator (GH-25285)
add:
_simple_enum decorator to transform a normal class into an enum
_test_simple_enum function to compare
_old_convert_ to enable checking _convert_ generated enums
_simple_enum takes a normal class and converts it into an enum:
@simple_enum(Enum)
class Color:
RED = 1
GREEN = 2
BLUE = 3
_old_convert_ works much like _convert_ does, using the original logic:
# in a test file
import socket, enum
CheckedAddressFamily = enum._old_convert_(
enum.IntEnum, 'AddressFamily', 'socket',
lambda C: C.isupper() and C.startswith('AF_'),
source=_socket,
)
test_simple_enum takes a traditional enum and a simple enum and
compares the two:
# in the REPL or the same module as Color
class CheckedColor(Enum):
RED = 1
GREEN = 2
BLUE = 3
_test_simple_enum(CheckedColor, Color)
_test_simple_enum(CheckedAddressFamily, socket.AddressFamily)
Any important differences will raise a TypeErrordiff --git a/Lib/test/test_ast.py b/Lib/test/test_ast.py
index 6824958..80d24e9 100644
--- a/Lib/test/test_ast.py
+++ b/Lib/test/test_ast.py
@@ -1,6 +1,7 @@
import ast
import builtins
import dis
+import enum
import os
import sys
import types
@@ -698,6 +699,35 @@ def test_constant_as_name(self):
with self.assertRaisesRegex(ValueError, f"Name node can't be used with '{constant}' constant"):
compile(expr, "<test>", "eval")
+ def test_precedence_enum(self):
+ class _Precedence(enum.IntEnum):
+ """Precedence table that originated from python grammar."""
+ TUPLE = enum.auto()
+ YIELD = enum.auto() # 'yield', 'yield from'
+ TEST = enum.auto() # 'if'-'else', 'lambda'
+ OR = enum.auto() # 'or'
+ AND = enum.auto() # 'and'
+ NOT = enum.auto() # 'not'
+ CMP = enum.auto() # '<', '>', '==', '>=', '<=', '!=',
+ # 'in', 'not in', 'is', 'is not'
+ EXPR = enum.auto()
+ BOR = EXPR # '|'
+ BXOR = enum.auto() # '^'
+ BAND = enum.auto() # '&'
+ SHIFT = enum.auto() # '<<', '>>'
+ ARITH = enum.auto() # '+', '-'
+ TERM = enum.auto() # '*', '@', '/', '%', '//'
+ FACTOR = enum.auto() # unary '+', '-', '~'
+ POWER = enum.auto() # '**'
+ AWAIT = enum.auto() # 'await'
+ ATOM = enum.auto()
+ def next(self):
+ try:
+ return self.__class__(self + 1)
+ except ValueError:
+ return self
+ enum._test_simple_enum(_Precedence, ast._Precedence)
+
class ASTHelpers_Test(unittest.TestCase):
maxDiff = None