How can I check nbr of cores of computer?

[defn noob]

How can I check how many cores my computer has?
Is it possible to do this in a Python-app?

[gbs]

On Tue, 29 Jul 2008 15:53:47 -0700, defn noob wrote:

How can I check how many cores my computer has? Is it possible to do
this in a Python-app?

Well you can try the functions in the 'platform' module, although in my
box(debian) nothing useful comes out. I don't think there's a simple &
portable way, you probably have to find one specific to your platform .
(if you are on linux, you can parse the output of 'cat /proc/cpuinfo')

[Mensanator]

On Jul 29, 5:53*pm, defn noob <[e-mail]:

How can I check how many cores my computer has?
Is it possible to do this in a Python-app?

If you're using Windows, get PyWin32:

win32api.GetSystemInfo
tuple = GetSystemInfo()

Retrieves information about the current system.

Win32 API References

Search for GetSystemInfo at msdn, google or google groups.

Return Value
The return value is a tuple of 9 values,
which corresponds to the Win32 SYSTEM_INFO structure.
The element names are:
dwOemId
dwPageSize
lpMinimumApplicationAddress
lpMaximumApplicationAddress
dwActiveProcessorMask
dwNumberOfProcessors
dwProcessorType
dwAllocationGranularity
(wProcessorLevel,wProcessorRevision)

>>import win32api
win32api.GetSystemInfo()

(0, 4096, 65536, 2147418111, 3L, 2, 586, 65536, (6, 3846))
|
processors

[alex.gaynor]

On Jul 29, 7:44*pm, Mensanator <[e-mail]:

On Jul 29, 5:53*pm, defn noob <[e-mail]:

How can I check how many cores my computer has?
Is it possible to do this in a Python-app?

If you're using Windows, get PyWin32:

win32api.GetSystemInfo
tuple = GetSystemInfo()

Retrieves information about the current system.

Win32 API References

Search for GetSystemInfo at msdn, google or google groups.

Return Value
The return value is a tuple of 9 values,
which corresponds to the Win32 SYSTEM_INFO structure.
The element names are:
dwOemId
dwPageSize
lpMinimumApplicationAddress
lpMaximumApplicationAddress
dwActiveProcessorMask
dwNumberOfProcessors
dwProcessorType
dwAllocationGranularity
(wProcessorLevel,wProcessorRevision)

>import win32api
win32api.GetSystemInfo()

(0, 4096, 65536, 2147418111, 3L, 2, 586, 65536, (6, 3846))
* * * * * * * * * * * * * * * * *|
* * * * * * * * * * * * * * * * *processors

This: http://pyprocessing.berlios.de/ has a method that returns CPU
count.

[John Nagle]

defn noob wrote:

How can I check how many cores my computer has?
Is it possible to do this in a Python-app?

Why do you care? Python can't use more than one of them at
a time anyway.

John Nagle

[Dan Upton]

On Wed, Jul 30, 2008 at 2:22 PM, John Nagle <na***@animats.comwrote:

defn noob wrote:

>>
How can I check how many cores my computer has?
Is it possible to do this in a Python-app?

Why do you care? Python can't use more than one of them at
a time anyway.

Per Python process, but you might fork multiple processes and want to
know how many cores there are to know how many to fork, and which
cores to pin them to. (I don't know if there's a direct way in Python
to force it to a certain core, so I instead just wrote an extension to
interface with sched_setaffinity on Linux.)

On Linux, an almost assuredly non-ideal way to find out the number of
cores is to read /proc/cpuinfo and look for the highest-numbered
"processor: " line (and add 1).

[Leonhard Vogt]

defn noob schrieb:

How can I check how many cores my computer has?
Is it possible to do this in a Python-app?

processing (http://pyprocessing.berlios.de/)
has an utility function processing.cpuCount().

Leo

[Daniel da Silva]

Single line using /proc/cpuinfo:

numprocs = [ int(line.strip()[-1]) for line in open('/proc/cpuinfo', 'r') if \
line.startswith('processor') ][-1] + 1
On Wed, Jul 30, 2008 at 2:16 PM, Dan Upton <up***@virginia.eduwrote:

>
On Wed, Jul 30, 2008 at 2:22 PM, John Nagle <na***@animats.comwrote:

defn noob wrote:

>
How can I check how many cores my computer has?
Is it possible to do this in a Python-app?

Why do you care? Python can't use more than one of them at
a time anyway.

Per Python process, but you might fork multiple processes and want to
know how many cores there are to know how many to fork, and which
cores to pin them to. (I don't know if there's a direct way in Python
to force it to a certain core, so I instead just wrote an extension to
interface with sched_setaffinity on Linux.)

On Linux, an almost assuredly non-ideal way to find out the number of
cores is to read /proc/cpuinfo and look for the highest-numbered
"processor: " line (and add 1).
--
http://mail.python.org/mailman/listinfo/python-list

[Steven D'Aprano]

On Wed, 30 Jul 2008 11:22:12 -0700, John Nagle wrote:

defn noob wrote:

>How can I check how many cores my computer has? Is it possible to do
this in a Python-app?

Why do you care? Python can't use more than one of them at
a time anyway.

Why do you care why he cares? And he didn't ask how to *use* multiple
cores, but how to detect if they're there.

Maybe all he wants is to write a toy program that outputs "Hello Fred,
your computer has N cores in the CPU. Have a nice day!".

I don't expect that Python will have a built-in core-counting function.
You would probably need to ask the operating system. On Linux, you could
do this:

import os
text = os.popen('cat /proc/cpuinfo').read()
How you would do it in Windows or Mac, I have no idea.

--
Steven

[Duncan Booth]

Steven D'Aprano <st***@REMOVE-THIS-cybersource.com.auwrote:

I don't expect that Python will have a built-in core-counting function.
You would probably need to ask the operating system. On Linux, you could
do this:

import os
text = os.popen('cat /proc/cpuinfo').read()
How you would do it in Windows or Mac, I have no idea.

One way on windows:

>>import win32pdhutil
def howmanycores():

for i in range(9999):
try: win32pdhutil.GetPerformanceAttributes("Processor(% d)" % i,"%
Processor Time")
except: break
return i

>>print howmanycores()

2

--
Duncan Booth http://kupuguy.blogspot.com