The issue is resolved by updating the CMakelists.txt as below.
cmake_minimum_required(VERSION 3.15)
project(test)
include(FindPythonInterp)
set (py_cmd “myhtml.py”)
execute_process(
COMMAND ${PYTHON_EXECUTABLE} ${py_cmd}
WORKING_DIRECTORY ${PROJECT_SOURCE_DIR}
RESULT_VARIABLE py_result1)
message(STATUS “Python result:” ${py_result1})