I just created my first application for Google App Engines, which is called "Hello World". It was the first lesson from Google App Engines How-to-get-started tutorial. I tested it on my computer (I am using Windows XP), and it was working just fine - whenever I would open a new window with my web browser (FireFox), I would always be able to see this phrase Hello, world!!!, which was a proof that it worked.
Before I created it I didn't know how to save a notepad file as a .py file. I asked this question here and quickly received an answer.
However, later I received a comment to my question saying this:
"App Engine does not support Python 2.6. You will have better luck using a Python 2.5 release. Sad, but true."
So I uninstalled Python 2.6.4 and installed Python 2.5.4. Also I uninstalled the Google App Engine Launcher and re-installed it again. While I was installing it a window popped saying that all the necessary prerequisites on my computer were found.
However, when I added my existed application and wanted to run it with App Engine Launcher, a message popped saying this:
"Python interpreter None not found. Cannot run project E:\python\helloworld. Please confirm these values in your Preferences, or take an appropriate measure to fix it (e.g. install Python)."
I tried deleting my application and re-make it anew - to no avail. What should I do?
Well, it is basically saying that it cannot find your just installed python interpreter.
It looks like you are on Windows so check your environment variables, particularly PATH and PYTHONPATH, they are probably still pointing to the previous 2.6 installation folder.