Fix Syntax and Deprecation Warnings from 3.12.

Python 3.12 highlighted a few Syntax and Deprecation
warnings. This updates the code base to fix the issues
highlighted (mostly use of raw strings for regex and
`ast.Constant` to replace `ast.Num`).

numba/np/ufunc/array_exprs.py

@@ -298,7 +298,7 @@ def _arr_expr_to_ast(expr):
                         lineno=expr.loc.line,
                         col_offset=expr.loc.col if expr.loc.col else 0), {}
     elif isinstance(expr, ir.Const):
-        return ast.Num(expr.value), {}
+        return ast.Constant(expr.value), {}
     raise NotImplementedError(
         "Don't know how to translate array expression '%r'" % (expr,))
 

numba/tests/test_dictobject.py

@@ -1303,7 +1303,7 @@ def test_exception_nargs(self):
             Dict(1, 2)
 
     def test_exception_mapping_ctor(self):
-        msg = '.*dict\(mapping\) is not supported.*'  # noqa: W605
+        msg = r'.*dict\(mapping\) is not supported.*'  # noqa: W605
         with self.assertRaisesRegex(TypingError, msg):
             Dict({1: 2})
 

numba/tests/test_parfors.py

@@ -4131,9 +4131,9 @@ def test_impl():
         cres = self.compile_parallel_fastmath(pfunc, ())
         ir = self._get_gufunc_ir(cres)
         _id = '%[A-Z_0-9]?(.[0-9]+)+[.]?[i]?'
-        recipr_str = '\s+%s = fmul fast double %s, 5.000000e-01'
+        recipr_str = r'\s+%s = fmul fast double %s, 5.000000e-01'
         reciprocal_inst = re.compile(recipr_str % (_id, _id))
-        fadd_inst = re.compile('\s+%s = fadd fast double %s, %s'
+        fadd_inst = re.compile(r'\s+%s = fadd fast double %s, %s'
                                % (_id, _id, _id))
         # check there is something like:
         #  %.329 = fmul fast double %.325, 5.000000e-01
@@ -4582,7 +4582,7 @@ def get_gufunc_asm(self, func, schedule_type, *args, **kwargs):
             asm = self._get_gufunc_asm(cres)
 
             if assertions:
-                schedty = re.compile('call\s+\w+\*\s+@do_scheduling_(\w+)\(')
+                schedty = re.compile(r'call\s+\w+\*\s+@do_scheduling_(\w+)\(')
                 matches = schedty.findall(cres.library.get_llvm_str())
                 self.assertGreaterEqual(len(matches), 1) # at least 1 parfor call
                 self.assertEqual(matches[0], schedule_type)

numba/tests/test_svml.py

@@ -171,7 +171,7 @@ class TestSVMLGeneration(TestCase):
     # env mutating, must not run in parallel
     _numba_parallel_test_ = False
     # RE for a generic symbol reference and for each particular SVML function
-    asm_filter = re.compile('|'.join(['\$[a-z_]\w+,']+list(svml_funcs)))
+    asm_filter = re.compile('|'.join([r'\$[a-z_]\w+,']+list(svml_funcs)))
 
     @classmethod
     def mp_runner(cls, testname, outqueue):

numba/tests/test_typingerror.py

@@ -207,7 +207,7 @@ def test_unsupported_type(self):
             cfunc(1, foo, 1)
 
         expected=re.compile(("This error may have been caused by the following "
-                             "argument\(s\):\\n- argument 1:.*Cannot determine "
+                             r"argument\(s\):\n- argument 1:.*Cannot determine "
                              "Numba type of "
                              "<class \'numba.tests.test_typingerror.Foo\'>"))
         self.assertTrue(expected.search(str(raises.exception)) is not None)

numba/tests/test_withlifting.py

@@ -548,7 +548,7 @@ def foo(x):
             njit(foo)(123)
         # Check that an error occurred in with-lifting in objmode
         pat = ("During: resolving callee type: "
-               "type\(ObjModeLiftedWith\(<.*>\)\)")
+               r"type\(ObjModeLiftedWith\(<.*>\)\)")
         self.assertRegex(str(raises.exception), pat)
 
     def test_case07_mystery_key_error(self):
@@ -822,7 +822,7 @@ def global_var():
         with self.assertRaisesRegex(
             errors.CompilerError,
             ("Error handling objmode argument 'val'. "
-             "Global 'gv_type2' is not defined\.")
+             r"Global 'gv_type2' is not defined.")
         ):
             global_var()