Python virtualenv activate.bat (Windows) - derive prompt title from virtualenv directory's parent

activate.bat

@echo off
set "VIRTUAL_ENV=C:\path\to\project\venv"

CALL :RESOLVE "%VIRTUAL_ENV%\.." PromptName
for %%f in (%PromptName%) do set PromptName=%%~nxf

if defined _OLD_VIRTUAL_PROMPT (
    set "PROMPT=%_OLD_VIRTUAL_PROMPT%"
) else (
    if not defined PROMPT (
        set "PROMPT=$P$G"
    )
    set "_OLD_VIRTUAL_PROMPT=%PROMPT%"
)
set "PROMPT=(%PromptName%) %PROMPT%"

REM Don't use () to avoid problems with them in %PATH%
if defined _OLD_VIRTUAL_PYTHONHOME goto ENDIFVHOME
    set "_OLD_VIRTUAL_PYTHONHOME=%PYTHONHOME%"
:ENDIFVHOME

set PYTHONHOME=

REM if defined _OLD_VIRTUAL_PATH (
if not defined _OLD_VIRTUAL_PATH goto ENDIFVPATH1
    set "PATH=%_OLD_VIRTUAL_PATH%"
:ENDIFVPATH1
REM ) else (
if defined _OLD_VIRTUAL_PATH goto ENDIFVPATH2
    set "_OLD_VIRTUAL_PATH=%PATH%"
:ENDIFVPATH2

set "PATH=%VIRTUAL_ENV%\Scripts;%PATH%"

GOTO :EOF
:RESOLVE
SET %2=%~f1
GOTO :EOF