compilation.md

@@ -24,10 +24,14 @@ make
 
 #### Python selection ####
 
-It is really important that the compilation process get access to the python version that the user want to use with lmgc90. As such, it possible to specify the absolute path to the python executable. For an example, to use python3 on ubuntu 18, one must run:
+It is really important that the compilation process get access to the python version
+that the user want to use with lmgc90. As such, it possible to specify the absolute path
+to the python executable. For an example, to use python3 on ubuntu 18,
+one must run the next line by replacing `[absolute path to python]` by `/usr/bin/python3`.
+Whereas a macos user will use `/opt/local/bin/python`.
 ```shell
 cd build
-cmake .. -DPYTHON_EXECUTABLE=/usr/bin/python3
+cmake .. -DPYTHON_EXECUTABLE=[absolute path to python]
 make
 ```