use assert[Not]In where appropriate
A patch from Dave Malcolm.
diff --git a/Lib/test/test_csv.py b/Lib/test/test_csv.py
index 75d1a91..29e54f7 100644
--- a/Lib/test/test_csv.py
+++ b/Lib/test/test_csv.py
@@ -811,7 +811,7 @@
# given that all three lines in sample3 are equal,
# I think that any character could have been 'guessed' as the
# delimiter, depending on dictionary order
- self.assertTrue(dialect.delimiter in self.sample3)
+ self.assertIn(dialect.delimiter, self.sample3)
dialect = sniffer.sniff(self.sample3, delimiters="?,")
self.assertEqual(dialect.delimiter, "?")
dialect = sniffer.sniff(self.sample3, delimiters="/,")