Merge pull request #278 from okdshin/python3_support

make python versions changeable

CMakeLists.txt

@@ -43,6 +43,10 @@ set( INCLUDE_ALE         OFF CACHE BOOL ${INCLUDE_ALE_DESC} )
 set( INCLUDE_CSHARP      ON  CACHE BOOL ${INCLUDE_CSHARP_DESC} )
 set( INCLUDE_JAVA        ON  CACHE BOOL ${INCLUDE_JAVA_DESC} )
 set( INCLUDE_PYTHON      ON  CACHE BOOL ${INCLUDE_PYTHON_DESC} )
+if( INCLUDE_PYTHON )
+  set( USE_PYTHON_VERSIONS_DESC "Specifies which versions of Python to build Malmo with Python bindings" )
+  set( USE_PYTHON_VERSIONS 2.7 CACHE STRING ${USE_PYTHON_VERSIONS_DESC} )
+endif()
 if( UNIX AND NOT APPLE )
   set( INCLUDE_LUA       ON  CACHE BOOL ${INCLUDE_LUA_DESC} )
   set( INCLUDE_TORCH     ON  CACHE BOOL ${INCLUDE_TORCH_DESC} )
@@ -122,8 +126,9 @@ if( INCLUDE_JAVA )
 endif()
 
 if( INCLUDE_PYTHON )
-  find_package( PythonInterp 2.7 REQUIRED )
-  find_package( PythonLibs 2.7 REQUIRED )
+  set( Python_ADDITIONAL_VERSIONS ${USE_PYTHON_VERSIONS} )
+  find_package( PythonInterp ${USE_PYTHON_VERSIONS} REQUIRED )
+  find_package( PythonLibs ${USE_PYTHON_VERSIONS} REQUIRED )
 endif()
 
 find_package( SWIG REQUIRED )