Use support.inject_memory_error_cm()

Author: vstinner

Lib/test/test_capi/test_bytes.py

@@ -567,11 +567,8 @@ def test_format_s_memory_error(self):
         writer = self.create_writer()
         s = b'x' * 500
         with self.assertRaises(MemoryError):
-            try:
-                _testcapi.set_nomemory(0, 0)
+            with support.inject_memory_error_cm():
                 writer.format_s(b's=%s', s)
-            finally:
-                _testcapi.remove_mem_hooks()
         writer.write_bytes(b'after', -1)
 
     @threading_helper.requires_working_threading()

Lib/test/test_dict.py

@@ -465,11 +465,8 @@ def test_copy_empty_no_memory(self):
         d = {}
         d_copy = d.copy
         with self.assertRaises(MemoryError):
-            try:
-                _testcapi.set_nomemory(0)
+            with support.inject_memory_error_cm():
                 d_copy()
-            finally:
-                _testcapi.remove_mem_hooks()
 
     def test_get(self):
         d = {}