python在linux系统下获取系统内存使用情况的方法

"""Simple module for getting amount of memory used by a specified user's processes on a UNIX system.It uses UNIX ps utility to get the memory usage for a specified username and pipe it to awk for summing upper application memory usage and return the total.Python's Popen() from subprocess module is used for spawning ps and awk."""import subprocessclass MemoryMonitor(object):  def __init__(self, username):    """Create new MemoryMonitor instance."""    self.username = username  def usage(self):    """Return int containing memory used by user's processes."""    self.process = subprocess.Popen("ps -u %s -o rss | awk '{sum+=$1} END {print sum}'" % self.username,                    shell=True,                    stdout=subprocess.PIPE,                    )    self.stdout_list = self.process.communicate()[0].split('/n')    return int(self.stdout_list[0])

from memorymonitor import MemoryMonitormemory_mon = MemoryMonitor('username')used_memory = memory_mon.usage()