[Python-Dev] isatty() on closed StringIO

Fri Nov 18 17:51:51 CET 2005

Paul Svensson wrote:
> On 2005年11月18日, Walter Dörwald wrote:
>>> BTW, isatty() has a similar problem:
>>>> >>> import StringIO, cStringIO
>> >>> s = StringIO.StringIO()
>> >>> s.close()
>> >>> s.isatty()
>> Traceback (most recent call last):
>> File "<stdin>", line 1, in ?
>> File "/usr/local/lib/python2.4/StringIO.py", line 93, in isatty
>> _complain_ifclosed(self.closed)
>> File "/usr/local/lib/python2.4/StringIO.py", line 40, in
>> _complain_ifclosed
>> raise ValueError, "I/O operation on closed file"
>> ValueError: I/O operation on closed file
>> >>> s = cStringIO.StringIO()
>> >>> s.close()
>> >>> s.isatty()
>> False
>>>> I guess cStringIO.StringIO.isatty() should raise an exception too.
>>> Why ? Is there any doubt that it's not a tty ?

No, but for real files a ValueError is raised too.
Bye,
 Walter Dörwald