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copied!<p>Use the preexec_fn parameter to subprocess.Popen, and the resource module. Example:</p> <p><em>parent.py:</em></p> <pre><code>#!/usr/bin/env python import os import sys import resource import subprocess def setlimits(): # Set maximum CPU time to 1 second in child process, after fork() but before exec() print "Setting resource limit in child (pid %d)" % os.getpid() resource.setrlimit(resource.RLIMIT_CPU, (1, 1)) print "CPU limit of parent (pid %d)" % os.getpid(), resource.getrlimit(resource.RLIMIT_CPU) p = subprocess.Popen(["./child.py"], preexec_fn=setlimits) print "CPU limit of parent (pid %d) after startup of child" % os.getpid(), resource.getrlimit(resource.RLIMIT_CPU) p.wait() print "CPU limit of parent (pid %d) after child finished executing" % os.getpid(), resource.getrlimit(resource.RLIMIT_CPU) </code></pre> <p><em>child.py:</em></p> <pre><code>#!/usr/bin/env python import os import sys import resource print "CPU limit of child (pid %d)" % os.getpid(), resource.getrlimit(resource.RLIMIT_CPU) </code></pre> <p><em>parent.py</em> will fork into a new process. In the new process, it will call setlimits(), then exec <em>child.py</em>. This means the resource will be limited in the child process, but not in the parent.</p> <p>Output when running program:</p> <pre><code>./parent.py CPU limit of parent (pid 17404) (-1, -1) Setting resource limit in child (pid 17405) CPU limit of parent (pid 17404) after startup of child (-1, -1) CPU limit of child (pid 17405) (1, 1) CPU limit of parent (pid 17404) after child finished executing (-1, -1) </code></pre> <p>This is in many cases a better solution than trying to use ulimit, since it's not always a good idea to spawn subprocess via shell, especially since it often causes ugly parameter quoting trouble.</p>

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