[Zope-dev] RE: python.exe vs pythonw.exe difference?

[Tim Peters]

[Thomas Heller]
> [I'm currently reading python-list via the gmane nntp interface, I
> don't know whether there really is a gmane.comp.web.zope.devel
> newsgroup]

I don't know either, so I'll copy you directly.

[Tim]
>> ...
>> Here's a Python program to try:
>>
>> """
>> import sys
>> if 1:   # edit to 1 for stdout, 0 for stderr
>>     console = sys.stdout
>> else:
>>     console = sys.stderr
>>
>> import traceback
>> tb = file('tb.txt', 'w')
>>
>> try:
>>     i = 0
>>     while True:
>>         i += 1
>>         console.write('.')
>> except:
>>     print >> tb, "Died when trying to write byte", i
>>     traceback.print_exc(file=tb)
>>     tb.close()
>> """
>>
>> Under Win98SE, and regardless of whether it writes to stdout or
>> stderr, it dies when run under pythonw, and tb.txt contains this
>> after:
>>
>> Died when trying to write byte 4097
>> Traceback (most recent call last):
>>   File "wr.py", line 14, in ?
>>     console.write('.')
>> IOError: [Errno 9] Bad file descriptor

[Thomas]
> I get exactly the same, on Win XP Pro, both for sys.stdout and
> sys.stderr.

That's good to know!  Thanks.

> ...
> Since it seems XP shows the same behaviour than win98SE, has the
> behaviour of Python changed?  Were IOErrors ignored on sys.stdout or
> sys.stderr in earlier versions?

No, the same program fails the same way here under pythonw 2.2.3 and 2.1.3
(with s/file/open/ and s/True/1/).  The OP wasn't clear about what "it"
meant, though (in "it used to work").  I guess it's most likely he meant
running Zope 2.5 as a service used to work, not that running Zope 2.5 by
hand from a DOS box with pythonw used to work, but don't know.  It's
certainly possible that something relevant changed in Zope, and/or in how
Zope tries to live with Windows services.

> IIRC, /F first proposed that pythonw.exe should create a console to
> have a place to show tracebacks.  Sounds like a good idea to me.

Some way of having pythonw not drop output into the bit bucket has sounded
like a good idea to everyone for about a decade now <wink>.

ideas-ain't-code-ly y'rs  - tim