# How can I switch the python version from 3.6.7 to 2.7.13?

**URL:** <https://discourse.slicer.org/t/how-can-i-switch-the-python-version-from-3-6-7-to-2-7-13/6925>\
**Category:** Development\
**Created:** [May 25, 2019, 7:59am UTC](https://discourse.slicer.org/t/how-can-i-switch-the-python-version-from-3-6-7-to-2-7-13/6925 "2019-05-25T07:59:32Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![JaceYang](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/jaceyang/32/3686_2.png) [@JaceYang](https://discourse.slicer.org/u/JaceYang)\
**Post date:** [May 25, 2019, 7:59am UTC](https://discourse.slicer.org/t/how-can-i-switch-the-python-version-from-3-6-7-to-2-7-13/6925/1 "2019-05-25T07:59:32Z")

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For some purposes,I need the python 2.7.13 in Slicer to make some old code work.  
Is there anyone have done this thing before?  
Any help is appreciate.

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**Author:** ![lassoan](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/lassoan/32/13_2.png) [@lassoan](https://discourse.slicer.org/u/lassoan)\
**Post date:** [May 25, 2019, 12:04pm UTC](https://discourse.slicer.org/t/how-can-i-switch-the-python-version-from-3-6-7-to-2-7-13/6925/2 "2019-05-25T12:04:13Z")

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Recent preview versions of Slicer switched to Python3 and we will not ever go back to Python2. You need to make minor changes to your Python2 modules to make them compatible with Python3 as described in this topic:

> [@Updating slicer to work with python 3](https://discourse.slicer.org/t/updating-slicer-to-work-with-python-3/4662/17):
>
> hey @jcfr, thanks for all your replies…i was having the similar sort of question and your solutions worked for me. best regards!!