Python 2.7 in Resolve 16 on Windows:

Py2> print sys.path
[
 'C:\\WINDOWS\\SYSTEM32\\python27.zip', # doesn't exist
 'C:\\Python27\\DLLs',
 'C:\\Python27\\lib',
 'C:\\Python27\\lib\\plat-win', # doesn't exist
 'C:\\Python27\\lib\\lib-tk',
 'C:\\Program Files\\Blackmagic Design\\DaVinci Resolve',
 'C:\\Python27',
 'C:\\Python27\\lib\\site-packages'
]

Py2> print '\n'.join(sys.path)
	C:\WINDOWS\SYSTEM32\python27.zip
	C:\Python27\DLLs
	C:\Python27\lib
	C:\Python27\lib\plat-win
	C:\Python27\lib\lib-tk
	C:\Program Files\Blackmagic Design\DaVinci Resolve
	C:\Python27
	C:\Python27\lib\site-packages	

Py2> import os
Py2> print os.environ
{
 'TMP': 'C:\\Users\\ANDROM~1\\AppData\\Local\\Temp'
 'COMPUTERNAME': 'CINTEL'
 'USERDOMAIN': 'CINTEL'
 'INTEL_DEV_REDIST': 'C:\\Program Files (x86)\\Common Files\\Intel\\Shared Libraries\\'
 'PSMODULEPATH': 'C:\\WINDOWS\\system32\\WindowsPowerShell\\v1.0\\Modules\\;C:\\Program Files\\Intel\\Wired Networking\\'
 'COMMONPROGRAMFILES': 'C:\\Program Files\\Common Files'
 'PROCESSOR_IDENTIFIER': 'Intel64 Family 6 Model 63 Stepping 2, GenuineIntel'
 'PROGRAMFILES': 'C:\\Program Files'
 'PROCESSOR_REVISION': '3f02'
 'SYSTEMROOT': 'C:\\WINDOWS'
 'PATH': '
    C:\\Python27\\
    C:\\Python27\\Scripts
    C:\\WINDOWS\\system32
    C:\\WINDOWS
    C:\\WINDOWS\\System32\\Wbem
    C:\\WINDOWS\\System32\\WindowsPowerShell\\v1.0\\
    C:\\Perl64\\site\\bin
    C:\\Perl64\\bin
    c:\\bin
    C:\\WINDOWS\\System32\\OpenSSH\\
    C:\\Program Files (x86)\\NVIDIA Corporation\\PhysX\\Common
    C:\\WINDOWS\\system32
    C:\\WINDOWS
    C:\\WINDOWS\\System32\\Wbem
    C:\\WINDOWS\\System32\\WindowsPowerShell\\v1.0\\
    C:\\WINDOWS\\System32\\OpenSSH\\
    C:\\Program Files (x86)\\Intel\\OpenCL SDK\\3.0\\bin\\x86
    C:\\Program Files (x86)\\Intel\\OpenCL SDK\\3.0\\bin\\x64
    C:\\Program Files (x86)\\QuickTime\\QTSystem\\
    C:\\Users\\Andromeda\\AppData\\Local\\Microsoft\\WindowsApps
 '
 'PROGRAMFILES(X86)': 'C:\\Program Files (x86)'
 'COMSPEC': 'C:\\WINDOWS\\system32\\cmd.exe'
 'DRIVERDATA': 'C:\\Windows\\System32\\Drivers\\DriverData'
 'TEMP': 'C:\\Users\\ANDROM~1\\AppData\\Local\\Temp'
 'COMMONPROGRAMFILES(X86)': 'C:\\Program Files (x86)\\Common Files'
 'PROCESSOR_ARCHITECTURE': 'AMD64'
 'MIC_LD_LIBRARY_PATH': 'C:\\Program Files (x86)\\Common Files\\Intel\\Shared Libraries\\compiler\\lib\\mic'
 'ALLUSERSPROFILE': 'C:\\ProgramData'
 'LOCALAPPDATA': 'C:\\Users\\Andromeda\\AppData\\Local'
 'HOMEPATH': '\\Users\\Andromeda'
 'USERDOMAIN_ROAMINGPROFILE': 'CINTEL'
 'RG_UNIVERSE_FRAMEWORK_RESOURCEDIR': 'C:\\Program Files\\Red Giant\\RGFX'
 'PROGRAMW6432': 'C:\\Program Files'
 'USERNAME': 'Andromeda'
 'LOGONSERVER': '\\\\CINTEL'
 'SESSIONNAME': 'Console'
 'PROGRAMDATA': 'C:\\ProgramData'
 'ONEDRIVE': 'C:\\Users\\Andromeda\\OneDrive'
 'PATHEXT': '.COM;.EXE;.BAT;.CMD;.VBS;.VBE;.JS;.JSE;.WSF;.WSH;.MSC'
 'FP_NO_HOST_CHECK': 'NO'
 'WINDIR': 'C:\\WINDOWS'
 'APPDATA': 'C:\\Users\\Andromeda\\AppData\\Roaming'
 'HOMEDRIVE': 'C:'
 'SYSTEMDRIVE': 'C:'
 'NUMBER_OF_PROCESSORS': '48'
 'PROCESSOR_LEVEL': '6'
 'RG_GPU_FRAMEWORK_ENGINE_RESOURCEDIR': 'C:\\Program Files\\Red Giant\\RGFX'
 'COMMONPROGRAMW6432': 'C:\\Program Files\\Common Files'
 'OS': 'Windows_NT'
 'PUBLIC': 'C:\\Users\\Public'
 'USERPROFILE': 'C:\\Users\\Andromeda'
}