From fb099c9ef134166ecaf3905c0d8b2995245f3ded Mon Sep 17 00:00:00 2001
From: R David Murray <rdmurray@bitdance.com>
Date: Tue, 19 Nov 2013 13:16:20 -0500
Subject: [PATCH] #19449: Handle non-string keys when generating 'fieldnames'
error.
csv was handling non-string keys fine except for the error message
generated when a non-string key was not in 'fieldnames'.
Fix by Tomas Grahn, full patch-with-test by Vajrasky Kok (tweaked slightly).
---
Lib/csv.py | 2 +-
Lib/test/test_csv.py | 12 ++++++++++++
Misc/NEWS | 3 +++
3 files changed, 16 insertions(+), 1 deletion(-)
diff --git a/Lib/csv.py b/Lib/csv.py
index da3bc44e7a..a56eed88c8 100644
--- a/Lib/csv.py
+++ b/Lib/csv.py
@@ -146,7 +146,7 @@ class DictWriter:
wrong_fields = [k for k in rowdict if k not in self.fieldnames]
if wrong_fields:
raise ValueError("dict contains fields not in fieldnames: "
- + ", ".join(wrong_fields))
+ + ", ".join([repr(x) for x in wrong_fields]))
return [rowdict.get(key, self.restval) for key in self.fieldnames]
def writerow(self, rowdict):
diff --git a/Lib/test/test_csv.py b/Lib/test/test_csv.py
index 976e6205b7..479ebd9bf2 100644
--- a/Lib/test/test_csv.py
+++ b/Lib/test/test_csv.py
@@ -570,6 +570,18 @@ class TestDictFields(unittest.TestCase):
fileobj = StringIO()
self.assertRaises(TypeError, csv.DictWriter, fileobj)
+ def test_write_fields_not_in_fieldnames(self):
+ with TemporaryFile("w+", newline='') as fileobj:
+ writer = csv.DictWriter(fileobj, fieldnames = ["f1", "f2", "f3"])
+ # Of special note is the non-string key (issue 19449)
+ with self.assertRaises(ValueError) as cx:
+ writer.writerow({"f4": 10, "f2": "spam", 1: "abc"})
+ exception = str(cx.exception)
+ self.assertIn("fieldnames", exception)
+ self.assertIn("'f4'", exception)
+ self.assertNotIn("'f2'", exception)
+ self.assertIn("1", exception)
+
def test_read_dict_fields(self):
with TemporaryFile("w+") as fileobj:
fileobj.write("1,2,abc\r\n")
diff --git a/Misc/NEWS b/Misc/NEWS
index 897bbc23d7..4278e952f5 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -13,6 +13,9 @@ Core and Builtins
Library
-------
+- Issue #19449: in csv's writerow, handle non-string keys when generating the
+ error message that certain keys are not in the 'fieldnames' list.
+
- Fix test.support.bind_port() to not cause an error when Python was compiled
on a system with SO_REUSEPORT defined in the headers but run on a system
with an OS kernel that does not support that reasonably new socket option.
--
2.40.0