# Radiomics error - No module named ‘pywt’
**URL:** https://discourse.slicer.org/t/radiomics-error-no-module-named-pywt/19128
**Category:** Radiomics
**Created:** [August 9, 2021, 8:08pm UTC](https://discourse.slicer.org/t/radiomics-error-no-module-named-pywt/19128 "2021-08-09T20:08:33Z")
**Posts on this page:** 9
**Page:** 1
### Author:  [@hotsen](https://discourse.slicer.org/u/hotsen)
#### Post date: [August 9, 2021, 8:08pm UTC](https://discourse.slicer.org/t/radiomics-error-no-module-named-pywt/19128/1 "2021-08-09T20:08:33Z")
Another question: I am trying to from radiomics import getFeatureClasses, but got the error " No module named ‘pywt’ ". I fixed the problem using the code mentioned here [Slicer Radiomics error - #3 by fedorov](https://discourse.slicer.org/t/slicer-radiomics-error/14279/3) , and @fedorov said he has updated this. But both the stable version and preview release of Slicer have this error. Thank you.
Hotsen
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### Author:  [@fedorov](https://discourse.slicer.org/u/fedorov)
#### Post date: [August 11, 2021, 6:11pm UTC](https://discourse.slicer.org/t/radiomics-error-no-module-named-pywt/19128/2 "2021-08-11T18:11:54Z")
I tried, and I am unable to even install the extension - I do not know what happened and why it says it is incompatible with the nightly slicer. I posted that question separately [here](https://discourse.slicer.org/t/unable-to-install-extension-incompatible-with-slicer-r30110/19158).
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### Author:  [@lassoan](https://discourse.slicer.org/u/lassoan)
#### Post date: [August 12, 2021, 3:52am UTC](https://discourse.slicer.org/t/radiomics-error-no-module-named-pywt/19128/3 "2021-08-12T03:52:42Z")
Switch to the new-generation extension server happened just today. You can use a release from a couple of days back on the download page by specifying an offset, for example: [https://download.slicer.org/?offset=-3](https://download.slicer.org/?offset=-3) allows you to download the Slicer Preview Release from 3 days ago.
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### Author:  [@fedorov](https://discourse.slicer.org/u/fedorov)
#### Post date: [August 12, 2021, 3:11pm UTC](https://discourse.slicer.org/t/radiomics-error-no-module-named-pywt/19128/4 "2021-08-12T15:11:20Z")
@hotsen the pyradiomics self-test works fine for me on mac for the preview release from 3 days ago. What platform are you on?
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### Author:  [@hotsen](https://discourse.slicer.org/u/hotsen)
#### Post date: [August 12, 2021, 3:21pm UTC](https://discourse.slicer.org/t/radiomics-error-no-module-named-pywt/19128/5 "2021-08-12T15:21:11Z")
@fedorov I am using stable version 4.11.20210226 and preview release 4.13.0-2021-08-08
Enter “from radiomics import getFeatureClasses” in python interactor, will give you “No module named ‘pywt’ error”
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### Author:  [@hotsen](https://discourse.slicer.org/u/hotsen)
#### Post date: [August 12, 2021, 3:22pm UTC](https://discourse.slicer.org/t/radiomics-error-no-module-named-pywt/19128/6 "2021-08-12T15:22:08Z")
I am using Windows platform
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### Author:  [@fedorov](https://discourse.slicer.org/u/fedorov)
#### Post date: [August 12, 2021, 3:22pm UTC](https://discourse.slicer.org/t/radiomics-error-no-module-named-pywt/19128/7 "2021-08-12T15:22:54Z")
Thanks, this works fine for me on mac, and I have not tested on windows. I actually don’t have a windows machine, but will try to figure something out.
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### Author:  [@fedorov](https://discourse.slicer.org/u/fedorov)
#### Post date: [August 12, 2021, 3:43pm UTC](https://discourse.slicer.org/t/radiomics-error-no-module-named-pywt/19128/8 "2021-08-12T15:43:43Z")
@hotsen I have Windows 10 running on Mac in Parallels, and for me the self-test completes fine, and `from radiomics import getFeatureClasses` in the python console does not trigger any errors for the preview release 2021-08-08.
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### Author:  [@hotsen](https://discourse.slicer.org/u/hotsen)
#### Post date: [August 12, 2021, 7:11pm UTC](https://discourse.slicer.org/t/radiomics-error-no-module-named-pywt/19128/9 "2021-08-12T19:11:22Z")
That’s odd. I just downloaded the new preview release 2021-08-12, no errors anymore. Thank you for testing!