# Subprocess.call does not work!

**URL:** <https://discourse.slicer.org/t/subprocess-call-does-not-work/2837>\
**Category:** Support\
**Created:** [May 17, 2018, 10:00am UTC](https://discourse.slicer.org/t/subprocess-call-does-not-work/2837 "2018-05-17T10:00:16Z")\
**Posts on this page:** 1\
**Showing post:** 2

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**Author:** ![ihnorton](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/ihnorton/32/9_2.png) [@ihnorton](https://discourse.slicer.org/u/ihnorton)\
**Post date:** [May 17, 2018, 2:33pm UTC](https://discourse.slicer.org/t/subprocess-call-does-not-work/2837/2 "2018-05-17T14:33:05Z")

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> [@wpgao](#):
>
> Is there any difference between the two pythons?

Yes, Slicer’s python is [embedded](https://discourse.slicer.org/t/access-slicer-modules-and-libraries-in-pycharm/2765/2).

`subprocess.call` should generally work, however, it will block Slicer (GUI will freeze) until the call completes (you can use `Popen` or Slicer’s CLI infrastructure instead for asynchronous calls). I just tried `subprocess.call(['sleep', '10'])` on linux with a recent nightly, and it worked fine.

Please show a minimal example if you can – maybe someone will notice a problem.

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_[View the full topic](https://discourse.slicer.org/t/subprocess-call-does-not-work/2837)._