rwallace rwallace - 8 months ago 57
Python Question

Total memory used by Python process?

Is there a way for a Python program to determine how much memory it's currently using? I've seen discussions about memory usage for a single object, but what I need is total memory usage for the process, so that I can determine when it's necessary to start discarding cached data.


On Windows, you can use WMI (home page, cheeseshop):

def memory():
    import os
    from wmi import WMI
    w = WMI('.')
    result = w.query("SELECT WorkingSet FROM Win32_PerfRawData_PerfProc_Process WHERE IDProcess=%d" % os.getpid())
    return int(result[0].WorkingSet)

On Linux (from python cookbook

import os
_proc_status = '/proc/%d/status' % os.getpid()

_scale = {'kB': 1024.0, 'mB': 1024.0*1024.0,
          'KB': 1024.0, 'MB': 1024.0*1024.0}

def _VmB(VmKey):
    global _proc_status, _scale
     # get pseudo file  /proc/<pid>/status
        t = open(_proc_status)
        v =
        return 0.0  # non-Linux?
     # get VmKey line e.g. 'VmRSS:  9999  kB\n ...'
    i = v.index(VmKey)
    v = v[i:].split(None, 3)  # whitespace
    if len(v) < 3:
        return 0.0  # invalid format?
     # convert Vm value to bytes
    return float(v[1]) * _scale[v[2]]

def memory(since=0.0):
    '''Return memory usage in bytes.
    return _VmB('VmSize:') - since

def resident(since=0.0):
    '''Return resident memory usage in bytes.
    return _VmB('VmRSS:') - since

def stacksize(since=0.0):
    '''Return stack size in bytes.
    return _VmB('VmStk:') - since