When using the Python node in a workspace, the the following error occurs:  
"Error in node, 'Python Node':  Selected language is not currently available to execute."  

Possible causes:

• Python is not installed.  
• The path to the executable folder is not in the system PATH variable.
• Python is not installed to a central location.

Windows operating system only. Python 2.7.x and above.

SOLUTION ONE
Make sure a version of Python is installed.  IronPython is installed with Statistica and does not need to be installed separately.  IronPython will not be listed as an installed application under Programs and Features.     For any other version besides IronPython, for example Python 3.6, a separate install must be performed.  See more information here.  

SOLUTION TWO
Add the path to the Python executable folder to the system PATH variable.  The path should be something like C:\Program Files\Python36\.  
To add to the path, follow these steps:

1. Select Start, select Control Panel,  double click System, and select the Advanced tab.
2. Click Environment Variables. ...
3. In the Edit System Variable (or New System Variable) window, specify the value of the PATH environment variable so that it includes the path to the Python executable.

SOLUTION THREE
There may be problems with Python is installed to a specific user folder.  The reason may have to do with permissions.  To resolve this:



 

This articles discusses the Python node error "Select language is not currently available to execute."