homepage

When sending unexpected data via a socket's sentdo method, a TypeError
is raised with the fallowing message: "sendto() takes exactly 3
arguments (2 given)". But two arguments are sufficient.
Examples for Python 2.x:
import socket
my_socket = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
# this will succeed
my_socket.sendto("Foobar", ("localhost", 514))
# these will fail with above error message
my_socket.sendto(u"Umlaut ä", ("localhost", 514))
my_socket.sendto(1, ("localhost", 514))
Examples for Python 3:
import socket
my_socket = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
# this will succeed
my_socket.sendto("No Umlaut".encode("ascii"), ("localhost", 514))
# these will fail with above error message
my_socket.sendto("No Umlaut", ("localhost", 514))
my_socket.sendto(1, ("localhost", 514))

File $python/lib/python3.0/logging/handlers.py
Line 782 : a bytes object is required instead of a string.
As a consequence, encoding shall be specified : but which one ?
Is : 
 self.socket.sendto(msg, self.address)
Should look like :
 self.socket.sendto(bytes(msg,'ascii'), self.address)

Here's a patch, which performs argument checking in a way to be able to provide better error message like that:
>>> my_socket.sendto("No Umlaut", ("localhost", 514))
Traceback (most recent call last):
 File "<stdin>", line 1, in <module>
TypeError: 'str' does not support the buffer interface

ping?

This bug is very misleading in Py3, as the TypeError makes one think that a string is being passed rather than bytes (how else do you get a 2 argument function call wrong?). Very difficult to determine that this is not in fact the bug in a dynamically typed language :P

New changeset c61b72b0650d by Antoine Pitrou in branch '3.1':
Issue #5421: Fix misleading error message when one of socket.sendto()'s
http://hg.python.org/cpython/rev/c61b72b0650d
New changeset 2af7a6d765fd by Antoine Pitrou in branch '3.2':
Issue #5421: merge fix
http://hg.python.org/cpython/rev/2af7a6d765fd
New changeset 90cdc371a3b8 by Antoine Pitrou in branch 'default':
Issue #5421: merge fix
http://hg.python.org/cpython/rev/90cdc371a3b8 

Thank you for the patch! This is now fixed in 3.x.

New changeset 9222c9d747c1 by Ezio Melotti in branch '3.1':
#5421: add tests.
http://hg.python.org/cpython/rev/9222c9d747c1
New changeset 4b3352b49483 by Ezio Melotti in branch '3.2':
#5421: merge with 3.1.
http://hg.python.org/cpython/rev/4b3352b49483
New changeset 20273f2195ba by Ezio Melotti in branch 'default':
#5421: merge with 3.2.
http://hg.python.org/cpython/rev/20273f2195ba 

I backported the patch to 2.7 in 7c3a20b5943a, and added tests to the 3.x branches.