[3.14] gh-132813: Improve error messages for incorrect types and values of csv.Dialog attributes (GH-133241) (GH-135050)

Make them similar to PyArg_Parse error messages, mention None as
a possible value, show a wrong type and the string length.
(cherry picked from commit df98a47a61a274eb7427c6201ddabec9ffd30b0a)

Co-authored-by: Serhiy Storchaka <storchaka@gmail.com>

1 files changed, 35 insertions, 13 deletions

diff --git a/Lib/test/test_csv.py b/Lib/test/test_csv.py
index 9aace57..60feab2 100644
--- a/Lib/test/test_csv.py
+++ b/Lib/test/test_csv.py
@@ -1122,19 +1122,22 @@ class TestDialectValidity(unittest.TestCase):
         with self.assertRaises(csv.Error) as cm:
             mydialect()
         self.assertEqual(str(cm.exception),
-                         '"quotechar" must be a 1-character string')
+                         '"quotechar" must be a unicode character or None, '
+                         'not a string of length 0')
 
         mydialect.quotechar = "''"
         with self.assertRaises(csv.Error) as cm:
             mydialect()
         self.assertEqual(str(cm.exception),
-                         '"quotechar" must be a 1-character string')
+                         '"quotechar" must be a unicode character or None, '
+                         'not a string of length 2')
 
         mydialect.quotechar = 4
         with self.assertRaises(csv.Error) as cm:
             mydialect()
         self.assertEqual(str(cm.exception),
-                         '"quotechar" must be string or None, not int')
+                         '"quotechar" must be a unicode character or None, '
+                         'not int')
 
     def test_delimiter(self):
         class mydialect(csv.Dialect):
@@ -1151,31 +1154,32 @@ class TestDialectValidity(unittest.TestCase):
         with self.assertRaises(csv.Error) as cm:
             mydialect()
         self.assertEqual(str(cm.exception),
-                         '"delimiter" must be a 1-character string')
+                         '"delimiter" must be a unicode character, '
+                         'not a string of length 3')
 
         mydialect.delimiter = ""
         with self.assertRaises(csv.Error) as cm:
             mydialect()
         self.assertEqual(str(cm.exception),
-                         '"delimiter" must be a 1-character string')
+                         '"delimiter" must be a unicode character, not a string of length 0')
 
         mydialect.delimiter = b","
         with self.assertRaises(csv.Error) as cm:
             mydialect()
         self.assertEqual(str(cm.exception),
-                         '"delimiter" must be string, not bytes')
+                         '"delimiter" must be a unicode character, not bytes')
 
         mydialect.delimiter = 4
         with self.assertRaises(csv.Error) as cm:
             mydialect()
         self.assertEqual(str(cm.exception),
-                         '"delimiter" must be string, not int')
+                         '"delimiter" must be a unicode character, not int')
 
         mydialect.delimiter = None
         with self.assertRaises(csv.Error) as cm:
             mydialect()
         self.assertEqual(str(cm.exception),
-                         '"delimiter" must be string, not NoneType')
+                         '"delimiter" must be a unicode character, not NoneType')
 
     def test_escapechar(self):
         class mydialect(csv.Dialect):
@@ -1189,20 +1193,32 @@ class TestDialectValidity(unittest.TestCase):
         self.assertEqual(d.escapechar, "\\")
 
         mydialect.escapechar = ""
-        with self.assertRaisesRegex(csv.Error, '"escapechar" must be a 1-character string'):
+        with self.assertRaises(csv.Error) as cm:
             mydialect()
+        self.assertEqual(str(cm.exception),
+                         '"escapechar" must be a unicode character or None, '
+                         'not a string of length 0')
 
         mydialect.escapechar = "**"
-        with self.assertRaisesRegex(csv.Error, '"escapechar" must be a 1-character string'):
+        with self.assertRaises(csv.Error) as cm:
             mydialect()
+        self.assertEqual(str(cm.exception),
+                         '"escapechar" must be a unicode character or None, '
+                         'not a string of length 2')
 
         mydialect.escapechar = b"*"
-        with self.assertRaisesRegex(csv.Error, '"escapechar" must be string or None, not bytes'):
+        with self.assertRaises(csv.Error) as cm:
             mydialect()
+        self.assertEqual(str(cm.exception),
+                         '"escapechar" must be a unicode character or None, '
+                         'not bytes')
 
         mydialect.escapechar = 4
-        with self.assertRaisesRegex(csv.Error, '"escapechar" must be string or None, not int'):
+        with self.assertRaises(csv.Error) as cm:
             mydialect()
+        self.assertEqual(str(cm.exception),
+                         '"escapechar" must be a unicode character or None, '
+                         'not int')
 
     def test_lineterminator(self):
         class mydialect(csv.Dialect):
@@ -1223,7 +1239,13 @@ class TestDialectValidity(unittest.TestCase):
         with self.assertRaises(csv.Error) as cm:
             mydialect()
         self.assertEqual(str(cm.exception),
-                         '"lineterminator" must be a string')
+                         '"lineterminator" must be a string, not int')
+
+        mydialect.lineterminator = None
+        with self.assertRaises(csv.Error) as cm:
+            mydialect()
+        self.assertEqual(str(cm.exception),
+                         '"lineterminator" must be a string, not NoneType')
 
     def test_invalid_chars(self):
         def create_invalid(field_name, value, **kwargs):