https://github.com/python/cpython/commit/0e88be6f55f35ab045e57f9f869b893c15dcc099 commit: 0e88be6f55f35ab045e57f9f869b893c15dcc099 branch: main author: Jan-Eric Nitschke <[email protected]> committer: gpshead <[email protected]> date: 2025-11-12T00:32:26Z summary:
gh-138621: Increase test coverage for csv.DictReader and csv.Sniffer (GH-138622) * Increase test coverage for csv.DictReader and csv.Sniffer Previously there were no tests for the DictReader fieldnames setter, the case where a StopIteration was encountered when trying to determine the fieldnames from the content or the case where Sniffer could not find a delimiter. * Revert whitespace change to comment * Add a test that csv.Sniffer.has_header checks up to 20 rows * Replace name and age with letter and offset Co-authored-by: Bénédikt Tran <[email protected]> * Address review comment --------- Co-authored-by: Bénédikt Tran <[email protected]> Co-authored-by: Gregory P. Smith <[email protected]> files: M Lib/test/test_csv.py diff --git a/Lib/test/test_csv.py b/Lib/test/test_csv.py index 6be6a7ae222f02..df79840088abc3 100644 --- a/Lib/test/test_csv.py +++ b/Lib/test/test_csv.py @@ -918,6 +918,14 @@ def test_dict_reader_fieldnames_accepts_list(self): reader = csv.DictReader(f, fieldnames) self.assertEqual(reader.fieldnames, fieldnames) + def test_dict_reader_set_fieldnames(self): + fieldnames = ["a", "b", "c"] + f = StringIO() + reader = csv.DictReader(f) + self.assertIsNone(reader.fieldnames) + reader.fieldnames = fieldnames + self.assertEqual(reader.fieldnames, fieldnames) + def test_dict_writer_fieldnames_rejects_iter(self): fieldnames = ["a", "b", "c"] f = StringIO() @@ -933,6 +941,7 @@ def test_dict_writer_fieldnames_accepts_list(self): def test_dict_reader_fieldnames_is_optional(self): f = StringIO() reader = csv.DictReader(f, fieldnames=None) + self.assertIsNone(reader.fieldnames) def test_read_dict_fields(self): with TemporaryFile("w+", encoding="utf-8") as fileobj: @@ -1353,6 +1362,19 @@ class TestSniffer(unittest.TestCase): ghi\0jkl """ + sample15 = "\n\n\n" + sample16 = "abc\ndef\nghi" + + sample17 = ["letter,offset"] + sample17.extend(f"{chr(ord('a') + i)},{i}" for i in range(20)) + sample17.append("v,twenty_one") # 'u' was skipped + sample17 = '\n'.join(sample17) + + sample18 = ["letter,offset"] + sample18.extend(f"{chr(ord('a') + i)},{i}" for i in range(21)) + sample18.append("v,twenty_one") # 'u' was not skipped + sample18 = '\n'.join(sample18) + def test_issue43625(self): sniffer = csv.Sniffer() self.assertTrue(sniffer.has_header(self.sample12)) @@ -1374,6 +1396,11 @@ def test_has_header_regex_special_delimiter(self): self.assertIs(sniffer.has_header(self.sample8), False) self.assertIs(sniffer.has_header(self.header2 + self.sample8), True) + def test_has_header_checks_20_rows(self): + sniffer = csv.Sniffer() + self.assertFalse(sniffer.has_header(self.sample17)) + self.assertTrue(sniffer.has_header(self.sample18)) + def test_guess_quote_and_delimiter(self): sniffer = csv.Sniffer() for header in (";'123;4';", "'123;4';", ";'123;4'", "'123;4'"): @@ -1423,6 +1450,10 @@ def test_delimiters(self): self.assertEqual(dialect.quotechar, "'") dialect = sniffer.sniff(self.sample14) self.assertEqual(dialect.delimiter, '\0') + self.assertRaisesRegex(csv.Error, "Could not determine delimiter", + sniffer.sniff, self.sample15) + self.assertRaisesRegex(csv.Error, "Could not determine delimiter", + sniffer.sniff, self.sample16) def test_doublequote(self): sniffer = csv.Sniffer() _______________________________________________ Python-checkins mailing list -- [email protected] To unsubscribe send an email to [email protected] https://mail.python.org/mailman3//lists/python-checkins.python.org Member address: [email protected]
