这个问题看起来很奇怪,我尝试重现了一下,发现简单的“del”就足够了。为了演示,您可以运行以下代码:
import itertools
import pdb
def test():
a = "a"
for _ in itertools.repeat(None, 30):
a += a
pdb.set_trace()
del a
pdb.set_trace()
test()
首次断点处,您将看到它使用了大约1GB的RAM(您需要Python3.3入口):
Private + Shared = RAM used Program
4.0 KiB + 9.0 KiB = 13.0 KiB VisualGDB-DisownTTY-r1
4.0 KiB + 15.0 KiB = 19.0 KiB sharing-tests
4.0 KiB + 19.5 KiB = 23.5 KiB dhcpcd
4.0 KiB + 31.5 KiB = 35.5 KiB gdb
4.0 KiB + 36.0 KiB = 40.0 KiB vim [deleted]
4.0 KiB + 38.0 KiB = 42.0 KiB systemd-udevd
40.0 KiB + 10.0 KiB = 50.0 KiB init
24.0 KiB + 135.0 KiB = 159.0 KiB agetty (6)
12.0 KiB + 150.0 KiB = 162.0 KiB su (3)
88.0 KiB + 103.0 KiB = 191.0 KiB syslog-ng (2)
152.0 KiB + 55.0 KiB = 207.0 KiB crond
172.0 KiB + 81.0 KiB = 253.0 KiB python3.4
580.0 KiB + 220.5 KiB = 800.5 KiB sshd (3)
768.0 KiB + 932.0 KiB = 1.7 MiB bash (13)
2.8 MiB + 118.0 KiB = 2.9 MiB mongod
7.4 MiB + 109.0 KiB = 7.5 MiB tmux [deleted] (2)
1.0 GiB + 1.2 MiB = 1.0 GiB python3.3
---------------------------------
1.0 GiB
=================================
然后在第二个断点处,当我们删除变量时,内存被释放:
Private + Shared = RAM used Program
4.0 KiB + 9.0 KiB = 13.0 KiB VisualGDB-DisownTTY-r1
4.0 KiB + 15.0 KiB = 19.0 KiB sharing-tests
4.0 KiB + 19.5 KiB = 23.5 KiB dhcpcd
4.0 KiB + 31.5 KiB = 35.5 KiB gdb
4.0 KiB + 36.0 KiB = 40.0 KiB vim [deleted]
4.0 KiB + 38.0 KiB = 42.0 KiB systemd-udevd
40.0 KiB + 10.0 KiB = 50.0 KiB init
24.0 KiB + 135.0 KiB = 159.0 KiB agetty (6)
12.0 KiB + 150.0 KiB = 162.0 KiB su (3)
88.0 KiB + 103.0 KiB = 191.0 KiB syslog-ng (2)
152.0 KiB + 55.0 KiB = 207.0 KiB crond
172.0 KiB + 81.0 KiB = 253.0 KiB python3.4
584.0 KiB + 220.5 KiB = 804.5 KiB sshd (3)
768.0 KiB + 928.0 KiB = 1.7 MiB bash (13)
2.8 MiB + 118.0 KiB = 2.9 MiB mongod
5.1 MiB + 1.2 MiB = 6.3 MiB python3.3
7.4 MiB + 109.0 KiB = 7.5 MiB tmux [deleted] (2)
---------------------------------
20.3 MiB
=================================
现在,如果我们从函数中删除“del”,并在test()后设置断点:
import itertools
import pdb
def test():
a = "a"
for _ in itertools.repeat(None, 30):
a += a
pdb.set_trace()
test()
pdb.set_trace()
在终止之前,内存确实不会被释放:
Private + Shared = RAM used Program
4.0 KiB + 9.0 KiB = 13.0 KiB VisualGDB-DisownTTY-r1
4.0 KiB + 15.0 KiB = 19.0 KiB sharing-tests
4.0 KiB + 19.5 KiB = 23.5 KiB dhcpcd
4.0 KiB + 31.5 KiB = 35.5 KiB gdb
4.0 KiB + 36.0 KiB = 40.0 KiB vim [deleted]
4.0 KiB + 38.0 KiB = 42.0 KiB systemd-udevd
40.0 KiB + 10.0 KiB = 50.0 KiB init
24.0 KiB + 135.0 KiB = 159.0 KiB agetty (6)
12.0 KiB + 150.0 KiB = 162.0 KiB su (3)
160.0 KiB + 53.0 KiB = 213.0 KiB crond
172.0 KiB + 81.0 KiB = 253.0 KiB python3.4
628.0 KiB + 219.5 KiB = 847.5 KiB sshd (3)
836.0 KiB + 152.0 KiB = 988.0 KiB syslog-ng (2)
752.0 KiB + 957.0 KiB = 1.7 MiB bash (13)
2.8 MiB + 113.0 KiB = 2.9 MiB mongod
7.4 MiB + 108.0 KiB = 7.6 MiB tmux [deleted] (2)
1.0 GiB + 1.1 MiB = 1.0 GiB python3.3
---------------------------------
1.0 GiB
=================================
所以我的建议是?在使用完后,只需删除这个东西,如果不再需要它的话;)
[1.0]*10**7
的简单测试用例,并且使用psutil
观察到del
可以释放它,但是我的对象largeTempVariable
在其数据结构上非常复杂,超出范围并不能将其释放回操作系统。 - amos