如何在Python中获得对象在内存中占用的大小?
当前回答
使用以下函数获取python对象的实际大小:
import sys
import gc
def actualsize(input_obj):
memory_size = 0
ids = set()
objects = [input_obj]
while objects:
new = []
for obj in objects:
if id(obj) not in ids:
ids.add(id(obj))
memory_size += sys.getsizeof(obj)
new.append(obj)
objects = gc.get_referents(*new)
return memory_size
actualsize([1, 2, [3, 4, 5, 1]])
参考:https://towardsdatascience.com/the-strange-size-of-python-objects-in-memory-ce87bdfbb97f
其他回答
这可能比看起来要复杂得多,这取决于你想要如何计数。例如,如果您有一个int类型的列表,您是否需要包含对int类型引用的列表的大小?(即-列表,而不是包含在其中的内容),或者你想包括实际指向的数据,在这种情况下,你需要处理重复引用,以及如何防止重复计数当两个对象包含对同一对象的引用时。
您可能想要查看python内存分析器之一,例如pysizer,以查看它们是否满足您的需求。
我自己也遇到过很多次这个问题,我写了一个小函数(受到@aaron-hall的回答的启发)和测试,它完成了我所期望的sys。Getsizeof to do:
https://github.com/bosswissam/pysize
如果你对背景故事感兴趣,这就是
编辑:附上下面的代码以方便参考。要查看最新的代码,请检查github链接。
import sys
def get_size(obj, seen=None):
"""Recursively finds size of objects"""
size = sys.getsizeof(obj)
if seen is None:
seen = set()
obj_id = id(obj)
if obj_id in seen:
return 0
# Important mark as seen *before* entering recursion to gracefully handle
# self-referential objects
seen.add(obj_id)
if isinstance(obj, dict):
size += sum([get_size(v, seen) for v in obj.values()])
size += sum([get_size(k, seen) for k in obj.keys()])
elif hasattr(obj, '__dict__'):
size += get_size(obj.__dict__, seen)
elif hasattr(obj, '__iter__') and not isinstance(obj, (str, bytes, bytearray)):
size += sum([get_size(i, seen) for i in obj])
return size
你可以序列化对象,以获得与对象大小密切相关的度量值:
import pickle
## let o be the object whose size you want to measure
size_estimate = len(pickle.dumps(o))
如果您想测量无法pickle的对象(例如,由于lambda表达式),dill或cloudpickle可以是一种解决方案。
我用这个技巧…May在小对象上不准确,但我认为对于复杂对象(如pygame surface)比sys.getsizeof()更准确。
import pygame as pg
import os
import psutil
import time
process = psutil.Process(os.getpid())
pg.init()
vocab = ['hello', 'me', 'you', 'she', 'he', 'they', 'we',
'should', 'why?', 'necessarily', 'do', 'that']
font = pg.font.SysFont("monospace", 100, True)
dct = {}
newMem = process.memory_info().rss # don't mind this line
Str = f'store ' + f'Nothing \tsurface use about '.expandtabs(15) + \
f'0\t bytes'.expandtabs(9) # don't mind this assignment too
usedMem = process.memory_info().rss
for word in vocab:
dct[word] = font.render(word, True, pg.Color("#000000"))
time.sleep(0.1) # wait a moment
# get total used memory of this script:
newMem = process.memory_info().rss
Str = f'store ' + f'{word}\tsurface use about '.expandtabs(15) + \
f'{newMem - usedMem}\t bytes'.expandtabs(9)
print(Str)
usedMem = newMem
在我的windows 10, python 3.7.3,输出是:
store hello surface use about 225280 bytes
store me surface use about 61440 bytes
store you surface use about 94208 bytes
store she surface use about 81920 bytes
store he surface use about 53248 bytes
store they surface use about 114688 bytes
store we surface use about 57344 bytes
store should surface use about 172032 bytes
store why? surface use about 110592 bytes
store necessarily surface use about 311296 bytes
store do surface use about 57344 bytes
store that surface use about 110592 bytes
对于numpy数组,getsizeof不起作用-对我来说,它总是出于某种原因返回40:
from pylab import *
from sys import getsizeof
A = rand(10)
B = rand(10000)
然后(在ipython中):
In [64]: getsizeof(A)
Out[64]: 40
In [65]: getsizeof(B)
Out[65]: 40
不过令人高兴的是,:
In [66]: A.nbytes
Out[66]: 80
In [67]: B.nbytes
Out[67]: 80000