在 Python 中获取总物理内存

Question

如何以与分布无关的方式获取 Python 中的总物理内存？我不需要已用内存，只需要总物理内存。

Answer 1

跨平台解决方案的最佳选择是使用psutil 包（在PyPI 上可用）。

import psutil
    
psutil.virtual_memory().total  # total physical memory in Bytes

virtual_memory 的文档是 here。

Answer 2

使用 os.sysconf 在 Linux 上：

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

注意：

• SC_PAGE_SIZE 通常是 4096。
• SC_PAGESIZE 和 SC_PAGE_SIZE 相等。
• 有关详细信息，请参阅man sysconf。
• 对于 MacOS，根据用户报告，这适用于 Python 3.7，但不适用于 Python 3.8。

在 Linux 上使用 /proc/meminfo：

meminfo = dict((i.split()[0].rstrip(':'),int(i.split()[1])) for i in open('/proc/meminfo').readlines())
mem_kib = meminfo['MemTotal']  # e.g. 3921852

Answer 3

正则表达式适用于这类事情，并且可能有助于解决分布之间的任何细微差异。

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])

Answer 4

此代码在 Python 2.7.9 中无需任何外部库即可为我工作

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'

我们很容易得到Used Memory和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'