Are multiple python installs confusing to Arc?

Question

Hello,  I am wondering about multiple installations of Python on a work machine (running arc 10.2.1).  Python is installed to it's own folder with the installation of Arc.  When I install the Pythonwin script editor, another instance of python is installed. Does Arc use a default version when it is using python to run web upload tools (such as staging and compressing .sd files and creating map services on arconline/arcgisserver.)?  I'd appreciate input.

Regards,

Giles

bixb0012 · Answer

There are multiple ways to do it.  The following StackOverflow thread is a bit dated, but I believe all of the content still applies:  How to change the version of python that pyscripter uses.

GilesKingsley1 · Answer

Joshua,

Thanks for the clarification, but maybe you can elaborate on a specific technical issue.  I’ve got the “regular” python install going on, but I’ve also installed PyScripter.  When I attempt to import Arcpy (in a script), I get ImportError:  No module named arcpy.   Any hints?  It sounds like I have to connect pyscripter to my ArcGIS python folder.

Appreciated,

gk

bixb0012 · Answer

Multiple Python installs are typically more confusing for the user than ArcGIS or any IDEs.  ArcGIS for Desktop, I am not talking Pro just the "originals," has its own Python install and is configured to use that one.  As long as you don't go monkeying in the registry or config files, it will always use that bundled install no matter how many other installs you put on the machine.

What typically confuses users is having the Python file type associations changed by subsequent Python installs.  A user will have ArcGIS for Desktop installed but then install another Python installation.  When the user clicks on a Python file to run it, it might fail to import ArcPy because the Python file type association in Windows has been updated to the new non-bundled Python install.

What can also confuse users is installed 64-bit Background Geoprocessing because that changes the Python file type associations.  Although the 64-bit Python install is similar to the 32-bit one, there are differences in ArcPy that cause issues.  For example, 64-bit ArcGIS (including the bundled Python installs) don't read personal geodatabases so code that access data in personal geodatabases can bomb.

Overall, you will be fine.  As I mentioned above, the confusion is usually on the user end and not the application end.