Defining macros in CMake for use in source

CMakeLists.txt

cmake_minimum_required(VERSION 3.10)
project(Macro)

set(CMAKE_CXX_STANDARD 11)

add_executable(Macro main.cpp)
target_compile_definitions(Macro PUBLIC PATHTOPYTHONSCRIPT=\"${CMAKE_SOURCE_DIR}/bin/postprocessing/extractlinedata.py\")

macro.cpp

#include <iostream>
#include <limits>

int main()
{
    std::string  command = "pvpython " PATHTOPYTHONSCRIPT " -f test_liddrivencavity_re1000-00009.vtu -p1 0.5 0 0 -p2 0.5 1 0";
    std::cout << "The command is '" << command << "'\n";
    return 0;
}