This article describes how to specify the Python version in Statistica without PATH Variable using the "PythonEngine.xml".
Note: PythonEngine.xml is present in the ScriptEngines i.e the one of the sub-folder in the Statistica installation directory ( i.e. <Statistica Installation directory>\Statistica 13\ScriptEngines)
 

How to specify Python version in Statistica without PATH Variable?

Windows Only

There is a dedicated file i.e. PythonEngine.xml to specify the known installations of Python (different versions) can be given specific names. For Example -  
    <KnownInstallations>
      <KnownInstallation InstallPath="C:\Program Files (x86)\Python36-32\python.exe" InstallLabel="Python3.6" />
      <KnownInstallation InstallPath="C:\Python27\python.exe" InstallLabel="Python2.7" />
    </KnownInstallations>

Also, Mappings can be created to facilitate substituting the use of a specified instance of python with a different instance of python. For Example - 

<InstallationMappings>
      <InstallationMapping FromLabel="Python - 2.7.11" ToLabel="Python2.7"/>
       <InstallationMapping FromLabel="PreferredPython" ToLabel="Python3.6"/> 
       <InstallationMapping FromLabel="Python - 3.6.1" ToLabel="PreferredPython"/> 
    </InstallationMappings>

Note: Required necessary rights to modify this file under <Statistica Installation directory>\ScriptEngines