How can I get the total physical memory within Python in a distribution agnostic fashion? I don't need used memory, just the total physical memory.
4 Answers
your best bet for a cross-platform solution is to use the psutil package (available on PyPI).
import psutil
psutil.virtual_memory().total # total physical memory in Bytes
Documentation for virtual_memory
is here.
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1
mem = virtual_memory()
and then# total physical memory
? Sounds great Commented Aug 30, 2018 at 18:44 -
Future proofed with 2018/12/18: web.archive.org/web/20181228093919/https://… Commented Jan 2, 2019 at 17:17
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int(np.round(psutil.virtual_memory().total / (1024. **3))) with a tip from @Asclepius. Commented Feb 1, 2023 at 4:37
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total does not (always?) seem to return the total physical memory available. E.g. getting 33429086208 for a 32 GB machine. Expected (as reported by free): 34359738368– Joerg SCommented Jan 18 at 14:24
Using os.sysconf
on Linux:
import os
mem_bytes = os.sysconf('SC_PAGE_SIZE') * os.sysconf('SC_PHYS_PAGES') # e.g. 4015976448
mem_gib = mem_bytes/(1024.**3) # e.g. 3.74
Note:
SC_PAGE_SIZE
is often 4096.SC_PAGESIZE
andSC_PAGE_SIZE
are equal.- For more info, see
man sysconf
. - For MacOS, as per user reports, this works with Python 3.7 but not with Python 3.8.
Using /proc/meminfo
on Linux:
meminfo = dict((i.split()[0].rstrip(':'),int(i.split()[1])) for i in open('/proc/meminfo').readlines())
mem_kib = meminfo['MemTotal'] # e.g. 3921852
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1@sorin,
os.sysconf('SC_PHYS_PAGES')
apparently doesn't work on OS X. Although the OS X man page forsysconf
does make note of_SC_PHYS_PAGES
, this seems inaccessible via Python. You may have more luck withpsutil
. Alternatively, refer to the techniques used in the answers here. Commented Jul 17, 2015 at 18:58 -
2FWIW, the
os.sysconf()
approach also works with Python 3 and even under Solaris 10. Commented Aug 27, 2017 at 19:25 -
1I am happy to report that it's working on MacOS X 10.13 (High Sierra) with Python 3.6.4. Commented Apr 19, 2018 at 16:49
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1On MacOs, works fine on Python 3.7 but not on Python 3.8.3. Getting
ValueError: unrecognized configuration name
foros.sysconf('SC_PHYS_PAGES')
Commented Jun 26, 2020 at 18:40 -
1Ideally I would want to figure out how to do this without external dependencies such as
psutil
Commented Jun 27, 2020 at 1:09
Regular expressions work well for this sort of thing, and might help with any minor differences across distributions.
import re
with open('/proc/meminfo') as f:
meminfo = f.read()
matched = re.search(r'^MemTotal:\s+(\d+)', meminfo)
if matched:
mem_total_kB = int(matched.groups()[0])
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5
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I mistook distribution-agnostic for cross-platform... and now I see it's tagged Linux. my bad :) Commented Jun 21, 2018 at 0:19
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/proc/meminfo
seems not to work as expected on AWS: Why does/proc/meminfo
show 32GB when AWS instance has only 16GB? Commented Apr 29, 2020 at 11:16 -
1@JoshuaDetwiler You don't need to explicitly close files when using contexts like this. When the context (the with block) is closed the file will be with it. Commented Feb 12, 2021 at 15:08
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Also @martin-thoma What AWS image are you using, I do not have this issue with the latest amazonlinux2. Commented Feb 12, 2021 at 15:11
This code worked for me without any external library at Python 2.7.9
import os
mem=str(os.popen('free -t -m').readlines())
"""
Get a whole line of memory output, it will be something like below
[' total used free shared buffers cached\n',
'Mem: 925 591 334 14 30 355\n',
'-/+ buffers/cache: 205 719\n',
'Swap: 99 0 99\n',
'Total: 1025 591 434\n']
So, we need total memory, usage and free memory.
We should find the index of capital T which is unique at this string
"""
T_ind=mem.index('T')
"""
Than, we can recreate the string with this information. After T we have,
"Total: " which has 14 characters, so we can start from index of T +14
and last 4 characters are also not necessary.
We can create a new sub-string using this information
"""
mem_G=mem[T_ind+14:-4]
"""
The result will be like
1025 603 422
we need to find first index of the first space, and we can start our substring
from from 0 to this index number, this will give us the string of total memory
"""
S1_ind=mem_G.index(' ')
mem_T=mem_G[0:S1_ind]
print 'Summary = ' + mem_G
print 'Total Memory = ' + mem_T +' MB'
Easily we can get the Used Memory and Free Memory
"""
Similarly we will create a new sub-string, which will start at the second value.
The resulting string will be like
603 422
Again, we should find the index of first space and than the
take the Used Memory and Free memory.
"""
mem_G1=mem_G[S1_ind+8:]
S2_ind=mem_G1.index(' ')
mem_U=mem_G1[0:S2_ind]
mem_F=mem_G1[S2_ind+8:]
print 'Used Memory = ' + mem_U +' MB'
print 'Free Memory = ' + mem_F +' MB'
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1
/proc/meminfo
./proc/meminfo
should be available on pretty much all linux installs./proc/meminfo
becausesysconf
has the answer.