python - 将 "key : value"形式的字符串转换为列表或字典并提取值

Question

我需要使用 linux 命令提取系统的空闲内存

cat /proc/meminfo

输出是这样的:

MemTotal:        1979676 kB
MemFree:          396244 kB
Buffers:          265048 kB
Cached:           629892 kB
SwapCached:           60 kB
Active:           503916 kB
Inactive:         770644 kB
Active(anon):     116564 kB
Inactive(anon):   369112 kB
Active(file):     387352 kB
Inactive(file):   401532 kB
Unevictable:           0 kB
Mlocked:               0 kB
SwapTotal:       2025468 kB
SwapFree:        2025276 kB
Dirty:               208 kB
Writeback:             0 kB
AnonPages:        379692 kB
Mapped:            76752 kB
Shmem:            106056 kB
Slab:             253328 kB
SReclaimable:     231816 kB
SUnreclaim:        21512 kB
KernelStack:        2720 kB
PageTables:        22152 kB
NFS_Unstable:          0 kB
Bounce:                0 kB
WritebackTmp:          0 kB
CommitLimit:     3015304 kB
Committed_AS:    2489860 kB
VmallocTotal:   34359738367 kB
VmallocUsed:      538576 kB
VmallocChunk:   34359176332 kB
HardwareCorrupted:     0 kB
AnonHugePages:    210944 kB
HugePages_Total:       0
HugePages_Free:        0
HugePages_Rsvd:        0
HugePages_Surp:        0
Hugepagesize:       2048 kB
DirectMap4k:       38908 kB
DirectMap2M:     1988608 kB

现在，我只对前两行感兴趣，即参数 MemTotal 和 MemFree。我编写了以下代码来提取前 2 个参数:

mi_l=[]
mt_l=[]
mf_l=[]
mf=[]
mi_j=[]
mi_mt=[]
mi_mf=[]
t=0
for i in range(0,4):
    tn1.write("cat /proc/meminfo")
    tn1.write("\n")
    time.sleep(2)
    rd_buf = telnet.read_very_eager()
    mi=rd_buf.splitlines()[:3]
    print "splitlines :\n"+str(mi)
    for ln in mi:
        mi_l.append([int(p) for p in ln.split() if p.isdigit()])
print(mi_l)
for i in range(0,12):
    print(mi_l[i])
for i in range(4,12):
    if i%3!=0:
        mt_l.append(mi_l[i])
        avail_mem=mt_l[0]
        print(mt_l)
for i in range(0,6):
    if i%2!=0:
        mf_l.append(mt_l[i])
        print(mf_l)
for i in mf_l:
    t=t+i
print(t)
ram_free=t/3
print "Total Available Memory : "+str(avail_mem)+"Free RAM :"+str(ram_free)

如您所见，我尝试提取 MemFree 参数 3 次并取这 3 个值的平均值。但是我收到错误消息 unsupported operand types for '+' : 'int' and 'list' 这是当我意识到 mf_l 结果是列表中的列表时.获得我需要的东西的最佳方式是什么？如果有人建议调整代码或替代解决方案，那将很有帮助。

Answer 1

首先，您可以使用 head -n 2/proc/meminfo 而不是 cat/proc/meminfo 来仅获取 的前两行/proc/内存信息.

然后你可以从第二行中提取数字并将其转换为数字，如下所示:

import os

mem_free = 0
for i in range(4):
    tn1.write("head -n 2 /proc/meminfo")
    tn1.write("\n")
    time.sleep(2)
    rd_buf = telnet.read_very_eager()
    mi=rd_buf.splitlines()[:3]
    mem_free += int(mi[2].split()[1])

mem_free /= 4.0