使用 Python 获取总物理内存

问题描述：

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。

解决方案 1：

跨平台解决方案的最佳选择是使用psutil包（可在PyPI上获得）。

import psutil

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

文档virtual_memory在这里。

解决方案 2：

在Linux上使用 ：os.sysconf

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

笔记：

• SC_PAGE_SIZE通常为 4096。

• SC_PAGESIZE且SC_PAGE_SIZE相等。

• 欲了解更多信息，请参阅man sysconf。

• 对于MacOS，根据用户报告，它适用于 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

解决方案 3：

正则表达式对于这种事情很有效，并且可能有助于解决不同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])

解决方案 4：

这段代码在 Python 2.7.9 上无需任何外部库就可以运行

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
', 
'Mem:           925        591        334         14         30        355
', 
'-/+ buffers/cache:        205        719
', 
'Swap:           99          0         99
', 
'Total:        1025        591        434
']
 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'

我们可以轻松获得已用内存和可用内存

    """
        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'