Get mem info

getmeminfo.py

import platform
from subprocess import check_output, PIPE, CalledProcessError

# Linux man page for `/proc`:
# http://man7.org/linux/man-pages/man5/proc.5.html

# Windows documentation for `wmic OS`:
# https://docs.microsoft.com/en-us/windows/win32/cimwin32prov/cim-operatingsystem

# MacOS man page for `sysctl`:
# https://www.unix.com/man-page/osx/3/sysctl/
# MacOS man page for `vm_stat`:
# https://www.unix.com/man-page/osx/1/vm_stat/

# These params could be in a json file in the script directory?
os_params = {
    'Linux': {
        'cmd': [('cat', '/proc/meminfo')], 
        'kwds': {
            # output string fragment -> result dict key
            'MemTotal:': 'MemTotal', 
            'MemAvailable:': 'MemAvailable',
            },
        },
    'Windows': {
        'cmd': [
            ('wmic', 'OS','get', 'TotalVirtualMemorySize'),
            ('wmic', 'OS', 'get', 'FreeVirtualMemory'),
            ],
        'kwds': {
            # output string fragment -> result dict key
            'TotalVirtualMemorySize': 'MemTotal',
            'FreeVirtualMemory': 'MemAvailable',
            },
        },
    'Darwin': {
        'cmd': [
            ('sysctl', 'hw.memsize'),
            ('vm_stat'),
            ],
        'kwds': {
            # output string fragment -> result dict key
            'hw.memsize:': 'MemTotal',
            'free:': 'MemAvailable',
            },
        'units': {
            'MemTotal': 1, # Size is given in bytes.
            'MemAvailable': 4096, # Size is given in 4kB pages.
            },
        },
    }

system_name = platform.system()
params = os_params.get(system_name, {})

output = []
for cmd in params.get('cmd', []):
    try:
        out = check_output(cmd, stderr=PIPE)
    except (OSError, CalledProcessError) as e:
        print(f'Error: {e}')
        continue
    if system_name == 'Windows':
        # Windows output is spread over several lines, join them.
        out = b''.join(line for line in out.splitlines()) + b'\n'
    output.extend(out.decode().splitlines())
    

sys_info = {}

kwds = params.get('kwds', {})
for line in output:
    match = kwds.keys() & line.split()
    if match and len(match) == 1:
        k = kwds[match.pop()]
        v = int(''.join(c for c in str(line) if c.isdigit()) or 0)
        # MacOSX units for total and free differ, get fancy unit or assume kB.
        v *= params.get('units', {k: 1024})[k]
        # Store memory size in bytes
        sys_info[k] = v 
    elif len(match) > 1:
        print(f'Ambiguous output: {line}')

print(sys_info)