# Catalyst Python script pipelines are generating pyc files

**URL:** https://discourse.paraview.org/t/catalyst-python-script-pipelines-are-generating-pyc-files/4176
**Category:** In Situ Support
**Created:** [April 24, 2020, 2:21pm UTC](https://discourse.paraview.org/t/catalyst-python-script-pipelines-are-generating-pyc-files/4176 "2020-04-24T14:21:10Z")
**Posts on this page:** 4
**Page:** 1

<div class="post-metadata">

### Author: ![Andy\_Bauer](https://discourse.paraview.org/user_avatar/discourse.paraview.org/andy_bauer/32/5442_2.png) [@Andy\_Bauer](https://discourse.paraview.org/u/Andy_Bauer)
#### Post date: [April 24, 2020, 2:21pm UTC](https://discourse.paraview.org/t/catalyst-python-script-pipelines-are-generating-pyc-files/4176/1 "2020-04-24T14:21:10Z")

</div>

Hi,

Using ParaView master as of April 24, 2020, it seems as if Catalyst is again generating .pyc files for the Catalyst Python scripts during simulation runs. I’m fairly certain that we intentionally prevented this from happening previously so I’m wondering if this was a conscious decision or not, or if this is just my memory playing tricks on me. I can disable this behavior by setting the `PYTHONDONTWRITEBYTECODE` environment variable to 1 but I think that this should be the default behavior as others have found that when running at scale and having many MPI processes trying to do simultaneously create the .pyc file can cause some serious file IO issues at startup. Note that I’m linking with Python 2.7, if that matters.

Thoughts?

Thanks,  
Andy

---

<div class="post-metadata">

### Author: ![wascott](https://discourse.paraview.org/letter_avatar_proxy/v4/letter/w/8e8cbc/32.png) [@wascott](https://discourse.paraview.org/u/wascott)
#### Post date: [April 24, 2020, 3:52pm UTC](https://discourse.paraview.org/t/catalyst-python-script-pipelines-are-generating-pyc-files/4176/2 "2020-04-24T15:52:51Z")

</div>

@utkarsh.ayachit

---

<div class="post-metadata">

### Author: ![utkarsh.ayachit](https://discourse.paraview.org/user_avatar/discourse.paraview.org/utkarsh.ayachit/32/39_2.png) [@utkarsh.ayachit](https://discourse.paraview.org/u/utkarsh.ayachit)
#### Post date: [April 27, 2020, 4:46pm UTC](https://discourse.paraview.org/t/catalyst-python-script-pipelines-are-generating-pyc-files/4176/3 "2020-04-27T16:46:01Z")

</div>

I don’t think this has changed. Makes sense to add such a mode to avoid generation of pyc for Catalyst.

---

<div class="post-metadata">

### Author: ![Andy\_Bauer](https://discourse.paraview.org/user_avatar/discourse.paraview.org/andy_bauer/32/5442_2.png) [@Andy\_Bauer](https://discourse.paraview.org/u/Andy_Bauer)
#### Post date: [April 27, 2020, 4:47pm UTC](https://discourse.paraview.org/t/catalyst-python-script-pipelines-are-generating-pyc-files/4176/4 "2020-04-27T16:47:23Z")

</div>

Ok, I wrote code to do that and [here’s](https://gitlab.kitware.com/paraview/paraview/-/merge_requests/4067) the MR. I would just do it instead of having it be a mode though.