address review: test format attribute instead of pack()

Author: skirpichev

Lib/test/test_struct.py

@@ -588,9 +588,6 @@ def test_Struct_reinitialization(self):
         with self.assertWarns(DeprecationWarning):
             s.__init__('<ii')
         self.assertEqual(s.format, '<ii')
-        packed = b'\x01\x00\x00\x00\x02\x00\x00\x00'
-        self.assertEqual(s.pack(1, 2), packed)
-        self.assertEqual(s.unpack(packed), (1, 2))
 
     def check_sizeof(self, format_str, number_of_codes):
         # The size of 'PyStructObject'
@@ -800,38 +797,38 @@ def __init__(self):
 
         with self.assertWarns(DeprecationWarning):
             my_struct = MyStruct()
-        self.assertEqual(my_struct.pack(12345), b'\x30\x39')
+        self.assertEqual(my_struct.format, '>h')
 
         # New way, no warnings:
         class MyStruct(struct.Struct):
             def __new__(cls):
                 return super().__new__(cls, '>h')
         my_struct = MyStruct()
-        self.assertEqual(my_struct.pack(12345), b'\x30\x39')
+        self.assertEqual(my_struct.format, '>h')
 
         class MyStruct(struct.Struct):
             def __new__(cls, arg):
                 self = super().__new__(cls, '>h')
                 return self
 
         my_struct = MyStruct(5)
-        self.assertEqual(my_struct.pack(123), b'\x00{')
+        self.assertEqual(my_struct.format, '>h')
 
         class MyStruct(struct.Struct):
             def __init__(self, *args, **kwargs):
                 super().__init__('>h')
 
         with self.assertWarns(DeprecationWarning):
             my_struct = MyStruct('<h')
-        self.assertEqual(my_struct.pack(12345), b'\x30\x39')
+        self.assertEqual(my_struct.format, '>h')
 
         with self.assertWarns(DeprecationWarning):
             my_struct = MyStruct(5)
-        self.assertEqual(my_struct.pack(12345), b'\x30\x39')
+        self.assertEqual(my_struct.format, '>h')
 
         with self.assertWarns(DeprecationWarning):
             my_struct = MyStruct('>h')
-        self.assertEqual(my_struct.pack(12345), b'\x30\x39')
+        self.assertEqual(my_struct.format, '>h')
 
     def test_repr(self):
         s = struct.Struct('=i2H')