get_darwin_real_python.py

# On macOS, system python binaries like /usr/bin/python and $(xcrun -f python3)
# are shims. They do some light validation work and then spawn the "real" python
# binary. Find the "real" python by asking dyld -- sys.executable reports the
# wrong thing more often than not. This is also useful when we're running under
# a Homebrew python3 binary, which also appears to be some kind of shim.
def getDarwinRealPythonExecutable():
    import ctypes

    dyld = ctypes.cdll.LoadLibrary("/usr/lib/system/libdyld.dylib")
    namelen = ctypes.c_ulong(1024)
    name = ctypes.create_string_buffer(b"\000", namelen.value)
    dyld._NSGetExecutablePath(ctypes.byref(name), ctypes.byref(namelen))
    return name.value.decode("utf-8").strip()


print(getDarwinRealPythonExecutable())