Since Python 2.3, PyArg_ParseTuple and friends give a DeprecationWarning
for floating-point arguments where integers are expected.  From
http://www.python.org/download/releases/2.3/NEWS.txt:
- The PyArg_Parse functions now issue a DeprecationWarning if a float
  argument is provided when an integer is specified (this affects the 'b',
  'B', 'h', 'H', 'i', and 'l' codes).  Future versions of Python will
  raise a TypeError.
Can we turn that DeprecationWarning into a TypeError for 2.7?  (It's
already a TypeError in 3.x.) I'd like to see things like 'range(-0.3)'
and 'itertools.combinations(range(3), 5.1)' raise TypeError.
N.B. The relevant format codes in 2.7 include 'I' and 'n' in addition to
the six codes listed above.

+1.

+10. It would fix the os.urandom(1.2) bug. On Linux, os.urandom() displays
the following warnings and then go into an unlimited loop...
/usr/lib/python2.5/os.py:734: DeprecationWarning: integer argument expected,
got float
  bytes += read(_urandomfd, n - len(bytes))
read(1.2 - 1) ~> read(0.2) ~> read(0)...
Tolerate float as integers introduces "subtle" bugs like byte/unicode bugs...

+1 for a TypeError too.

I think this should be signalled on the mailing-list, by the way. I
expect everyone to agree of course :)

Yes, checking with python-dev sounds sensible.  I'll wait until there's
a working patch, though.

Hmm.  That's unfortunate:  for argument type in 'bBHiIlkKn', an attempt to
pass a float results in a DeprecationWarning.  For type 'L', there's no
DeprecationWarning, and the float is silently truncated.  So for type 'L'
I guess we still have to go through a round of DeprecationWarning.
I'm not sure what 'h' does;  there don't appear to be any tests for it,
currently.

'h' also produces a DeprecationWarning;  I just added the missing tests
for it in r76930 (trunk) and r76931 (py3k).

Here's a patch that makes the DeprecationWarning a TypeError, and adds a
new DeprecationWarning for the 'L' format.

Applied to trunk in r77218.  The DeprecationWarning for the 'L' format
needs to be merged to py3k.

Merged relevant bits to py3k in r77220.

stage: needs patch -> resolved

nosy: + pitrou
messages: + msg95497

stage: needs patch