diff --git a/scrapy/extensions/memusage.py b/scrapy/extensions/memusage.py
index 221967bda..ca766c938 100644
--- a/scrapy/extensions/memusage.py
+++ b/scrapy/extensions/memusage.py
@@ -128,9 +128,9 @@ class MemoryUsage:
     def _send_report(self, rcpts, subject):
         """send notification mail with some additional useful info"""
         stats = self.crawler.stats
-        s = f"Memory usage at engine startup : {stats.get_value('memusage/startup')/1024/1024}M\r\n"
-        s += f"Maximum memory usage          : {stats.get_value('memusage/max')/1024/1024}M\r\n"
-        s += f"Current memory usage          : {self.get_virtual_size()/1024/1024}M\r\n"
+        s = f"Memory usage at engine startup : {stats.get_value('memusage/startup') / 1024 / 1024}M\r\n"
+        s += f"Maximum memory usage          : {stats.get_value('memusage/max') / 1024 / 1024}M\r\n"
+        s += f"Current memory usage          : {self.get_virtual_size() / 1024 / 1024}M\r\n"
 
         s += (
             "ENGINE STATUS ------------------------------------------------------- \r\n"
diff --git a/tests/test_utils_iterators.py b/tests/test_utils_iterators.py
index 3598fa0bb..4a0c34d82 100644
--- a/tests/test_utils_iterators.py
+++ b/tests/test_utils_iterators.py
@@ -524,6 +524,6 @@ class TestHelper(unittest.TestCase):
 
     def _assert_type_and_value(self, a, b, obj):
         self.assertTrue(
-            type(a) is type(b), f"Got {type(a)}, expected {type(b)} for { obj!r}"
+            type(a) is type(b), f"Got {type(a)}, expected {type(b)} for {obj!r}"
         )
         self.assertEqual(a, b)