portable /dev/null

[Brendan Miller]

Hi,

I have functions that take a file object and write to it. In some cases I
just want to throw out what is written to that file object. I want
something like open('/dev/null', 'w'), but portable.

It needs to have an underlying file descriptor/file handle, as it will be
passed to non python code.

Is there a portable /dev/null somewhere in the standard library?

Thanks,
Brendan

 

[Giampaolo Rodola']

Hi,

I have functions that take a file object and write to it. In some cases I
just want to throw out what is written to that file object. I want
something like open('/dev/null', 'w'), but portable.

It needs to have an underlying file descriptor/file handle, as it will be
passed to non python code.

Is there a portable /dev/null somewhere in the standard library?

Thanks,
Brendan

I don't think so. You could define a dummy class emulating the file-
object API. Something like:

class NullDevice:
"A writeable object that writes to nowhere -- like /dev/null."
def write(self, s):
pass

closed = False
def close(self):
self.closed = True


--- Giampaolo
http://code.google.com/p/pyftpdlib

 

[Christian Heimes]

Hi,

I have functions that take a file object and write to it. In some cases I
just want to throw out what is written to that file object. I want
something like open('/dev/null', 'w'), but portable.

import os
null = open(os.devnull, "wb")



Christian

 

[Christian Heimes]

Hi,

I have functions that take a file object and write to it. In some cases I
just want to throw out what is written to that file object. I want
something like open('/dev/null', 'w'), but portable.

import os
null = open(os.devnull, "wb")



Christian

 

[Martin v. Löwis]

I have functions that take a file object and write to it. In some cases I

just want to throw out what is written to that file object. I want
something like open('/dev/null', 'w'), but portable.

It needs to have an underlying file descriptor/file handle, as it will be
passed to non python code.

Is there a portable /dev/null somewhere in the standard library?

The subprocess module should work fine. Pass a pipe to the subprocess,
and read and discard anything from the pipe (e.g. in a separate thread).
If the non-Python code is inprocess, you are out of luck. Some systems
just don't support a null device, so Python can't possibly emulate it.

Regards,
Martin

 

[Gabriel Genellina]

I have functions that take a file object and write to it. In some cases I
just want to throw out what is written to that file object. I want
something like open('/dev/null', 'w'), but portable.

It needs to have an underlying file descriptor/file handle, as it will be
passed to non python code.

Is there a portable /dev/null somewhere in the standard library?

py> import os
py> print os.devnull
nul

(this is on Windows)

 

[Brendan Miller]

import os
null = open(os.devnull, "wb")



Christian

Awesome. Thanks.

Brendan