Windows Python 2.4: Unbuffered flag causes SyntaxError on interactive sessions?

[Lonnie Princehouse]

>From the cmd shell on both Windows 2k and XP, I'm getting this weird
syntax error in conjunction with the unbuffered flag. It works fine
without -u. Has anyone else encountered it? This didn't happen with
Python 2.2...

C:\>python -u
Python 2.4.1 (#65, Mar 30 2005, 09:13:57) [MSC v.1310 32 bit (Intel)]
on win32
Type "help", "copyright" , "credits" or "license" for more information.[color=blue][color=green][color=darkred]
>>> print 'hello'[/color][/color][/color]
File "<stdin>", line 1
print 'hello'
^
SyntaxError: invalid syntax


(sorry if this is a known/fixed bug... I couldn't find anything about
it)

[Michael Hoffman]

Re: Windows Python 2.4: Unbuffered flag causes SyntaxError on interactivesess ions?

Lonnie Princehouse wrote:[color=blue]
> C:\>python -u
> Python 2.4.1 (#65, Mar 30 2005, 09:13:57) [MSC v.1310 32 bit (Intel)]
> on win32
> Type "help", "copyright" , "credits" or "license" for more information.
>[color=green][color=darkred]
>>>>print 'hello'[/color][/color]
>
> File "<stdin>", line 1
> print 'hello'
> ^
> SyntaxError: invalid syntax[/color]

Worksforme:

C:\Python24>pyt hon.exe -u
Python 2.4.1 (#65, May 24 2005, 13:43:04) [MSC v.1310 32 bit (Intel)] on
win32
Type "help", "copyright" , "credits" or "license" for more information.[color=blue][color=green][color=darkred]
>>> print 'hello'[/color][/color][/color]
hello

Strange that your python build is from 30 March and mine is from 24 May.
--
Michael Hoffman

[Irmen de Jong]

Re: Windows Python 2.4: Unbuffered flag causes SyntaxError on interactivesess ions?

Michael Hoffman wrote:[color=blue]
> Lonnie Princehouse wrote:
>[color=green]
>> C:\>python -u
>> Python 2.4.1 (#65, Mar 30 2005, 09:13:57) [MSC v.1310 32 bit (Intel)]
>> on win32
>> Type "help", "copyright" , "credits" or "license" for more information.
>>[color=darkred]
>>>>> print 'hello'[/color]
>>
>>
>> File "<stdin>", line 1
>> print 'hello'
>> ^
>> SyntaxError: invalid syntax[/color]
>
>
> Worksforme:
>
> C:\Python24>pyt hon.exe -u
> Python 2.4.1 (#65, May 24 2005, 13:43:04) [MSC v.1310 32 bit (Intel)] on
> win32
> Type "help", "copyright" , "credits" or "license" for more information.[color=green][color=darkred]
> >>> print 'hello'[/color][/color]
> hello
>
> Strange that your python build is from 30 March and mine is from 24 May.[/color]


Problem also occurs on my machine using Win XP Home,
Python 2.4.1 (#65, Mar 30 2005, 09:13:57) [MSC v.1310 32 bit (Intel)] on win32


even just typing "print" at the interactive prompt causes a syntax error...

--Irmen

[Lonnie Princehouse]

Re: Windows Python 2.4: Unbuffered flag causes SyntaxError on interactive sessions?

Weird. Did you build Python yourself? The 2.4.1 release on python.org
is from March 30.
I just tried ActiveState's 2.4.1... the same thing happens.

[Michael Hoffman]

Re: Windows Python 2.4: Unbuffered flag causes SyntaxError on interactivesess ions?

Lonnie Princehouse wrote:[color=blue]
> Weird. Did you build Python yourself?[/color]

No.
--
Michael Hoffman

[Terry Reedy]

Re: Windows Python 2.4: Unbuffered flag causes SyntaxErroronin teractive sessions?


"Lonnie Princehouse" <finite.automat on@gmail.com> wrote in message
news:1126644810 .073493.201700@ g43g2000cwa.goo glegroups.com.. .[color=blue]
> Weird. Did you build Python yourself? The 2.4.1 release on python.org
> is from March 30.
> I just tried ActiveState's 2.4.1... the same thing happens.[/color]

Please report this on the SourceForge bug list, including the details of
the two releases and de Jong's confirmation (and even Hoffman's
non-confirmation). The 2.4.2 release process starts soon and it would be
nice to have this fixed.

Terry J. Reedy

[Lonnie Princehouse]

Re: Windows Python 2.4: Unbuffered flag causes SyntaxError oninteractive sessions?

Will do

[Reinhold Birkenfeld]

Re: Windows Python 2.4: Unbuffered flag causes SyntaxError on interactivesess ions?

Irmen de Jong wrote:[color=blue]
> Michael Hoffman wrote:[color=green]
>> Lonnie Princehouse wrote:
>>[color=darkred]
>>> C:\>python -u
>>> Python 2.4.1 (#65, Mar 30 2005, 09:13:57) [MSC v.1310 32 bit (Intel)]
>>> on win32
>>> Type "help", "copyright" , "credits" or "license" for more information.
>>>
>>>>>> print 'hello'
>>>
>>>
>>> File "<stdin>", line 1
>>> print 'hello'
>>> ^
>>> SyntaxError: invalid syntax[/color]
>>
>>
>> Worksforme:
>>
>> C:\Python24>pyt hon.exe -u
>> Python 2.4.1 (#65, May 24 2005, 13:43:04) [MSC v.1310 32 bit (Intel)] on
>> win32
>> Type "help", "copyright" , "credits" or "license" for more information.[color=darkred]
>> >>> print 'hello'[/color]
>> hello
>>
>> Strange that your python build is from 30 March and mine is from 24 May.[/color]
>
>
> Problem also occurs on my machine using Win XP Home,
> Python 2.4.1 (#65, Mar 30 2005, 09:13:57) [MSC v.1310 32 bit (Intel)] on win32
>
>
> even just typing "print" at the interactive prompt causes a syntax error...[/color]

It __may__ be that this is caused by an error in the codecs machinery which is already
fixed in 2.4 CVS. Could you try this out?

Reinhold

[Lonnie Princehouse]

Re: Windows Python 2.4: Unbuffered flag causes SyntaxError oninteractive sessions?

After doing some more reading, I now think this isn't a bug.

Evidently the unbuffered flag not only makes stdin unbuffered, but it
also forces it into binary mode. I didn't realize that when I posted
earlier.

So the SyntaxErrors arise because the interpreter isn't converting \r\n
into \n because stdin is binary. Not a bug, although it would be nice
to have an "unbuffered text mode" flag too...

D'oh.

[Michael Hoffman]

Re: Windows Python 2.4: Unbuffered flag causes SyntaxError oninteractivese ssions?

Lonnie Princehouse wrote:
[color=blue]
> Evidently the unbuffered flag not only makes stdin unbuffered, but it
> also forces it into binary mode. I didn't realize that when I posted
> earlier.
>
> So the SyntaxErrors arise because the interpreter isn't converting \r\n
> into \n because stdin is binary. Not a bug, although it would be nice
> to have an "unbuffered text mode" flag too...[/color]

so if you do this:
[color=blue][color=green][color=darkred]
>>> z = raw_input()[/color][/color][/color]
zzz

Does z contain 'zzz\r'?

For me, it just contains 'zzz'.
--
Michael Hoffman

[Lonnie Princehouse]

Re: Windows Python 2.4: Unbuffered flag causes SyntaxError oninteractive sessions?

Yes. With the unbuffered flag, raw_input() strings on my box end in
\r.

[Steve Holden]

Re: Windows Python 2.4: Unbuffered flag causes SyntaxErroronin teractive sessions?

Lonnie Princehouse wrote:[color=blue]
> After doing some more reading, I now think this isn't a bug.
>
> Evidently the unbuffered flag not only makes stdin unbuffered, but it
> also forces it into binary mode. I didn't realize that when I posted
> earlier.
>
> So the SyntaxErrors arise because the interpreter isn't converting \r\n
> into \n because stdin is binary. Not a bug, although it would be nice
> to have an "unbuffered text mode" flag too...
>
> D'oh.
>[/color]
It seems a little bizarre to me that the compiler isn't prepared to
treat carriage returns as whitespace during its tokenizations. The only
area I would anticipate problems would be string literals containing
end-of-line sequences embedded within triple-quotes.

It would seem to make sense to program the compiler defensively to
ignore embedded "\r" characters.

regards
Steve
--
Steve Holden +44 150 684 7255 +1 800 494 3119
Holden Web LLC http://www.holdenweb.com/