Python 3.2 is already installed on my computer but ArcGIS wants version 2.7

[AliceZiegler]

Hey there,

while trying to use the "Raster Calculator", I got the error message that Python 2.7 is not installed.
That is right, as while installing ArcGIS I decided not to install PYthon 2.7 as I already use Python 3.2 on my computer.

Is there a possibility to change the settings so that ArcGIS uses the 3.2 version?
I definately need the 3.2 version of Python for other university stuff. Can I have two different versions of Python on my computer at the same time?
Or any other solution?

I really don't know how to solve the problem and would be very thankful for any advice...

Thanks

[MathewCoyle · Accepted solution]

ArcGIS requires python 2.7. It is not compatible with 3.x. Having 3.x and 2.7 installed at the same time is not recommended but you should be able to work around it. Just make sure you have the right file associations and system paths.

[AliceZiegler]

I installed Python 2.7.! But unfortunately I still get error messages. (But not the one, that ArcGIS can't find Python 2.7!) So, is there anything I need to do, to somehow "connect" ArcGIS with the newly installed Python 2.7? It's just not working!

I even thought about uninstalling ArcGIS, Python 3.x and Python 2.7, and starting all over again. But the "uninstall utility" only uninstalles the previous versions and I don't know how to uninstall 10.1 (but I guess I should post that in a different thread).

Any kind of help would be great!

[curtvprice]

I installed Python 2.7.! But unfortunately I still get error messages.

Check out this post about the Desktop.pth file:

[thread]23230[/thread]

Also - make sure Windows has .py files associated with python 2.7 python.exe.

[ThaiWood]

As other have said make sure that your path reflects the correct install of python.  If you installed python from python.org your install will most likely be in C:\python<version number> or C:\program files (x86)\python<version number>.  Check this out for screenshots of how to change your path on Windows 7 and XP.  Check here for how to change file associations.