diff --git a/CMakeLists.txt b/CMakeLists.txt
index 34660239e..75972a9d0 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -123,7 +123,15 @@ endif()
 
   include(java)
 
-if (${CMAKE_SYSTEM_NAME} MATCHES "Darwin")
+set(WITH_PYTHON YES CACHE FILEPATH "Try to use Python (currently Python 3)")
+
+if (WITH_PYTHON)
+  include(python)
+endif()
+
+
+if (
+)
   cmake_policy( SET CMP0042 NEW)
   #cmake_policy( NO_POLICY_SCOPE )
 endif()
diff --git a/CXX/yapi.cpp b/CXX/yapi.cpp
index a1d769317..edd0657fb 100644
--- a/CXX/yapi.cpp
+++ b/CXX/yapi.cpp
@@ -9,13 +9,13 @@ extern "C" {
 #include "blobs.h"
 
 X_API char *Yap_TermToString(Term t, char *s, size_t sz, size_t *length,
-                       encoding_t *encodingp, int flags);
+                             encoding_t *encodingp, int flags);
 
 X_API void YAP_UserCPredicate(const char *, YAP_UserCPred, YAP_Arity arity);
 X_API void YAP_UserCPredicateWithArgs(const char *, YAP_UserCPred, YAP_Arity,
-                                YAP_Term);
+                                      YAP_Term);
 X_API void YAP_UserBackCPredicate(const char *, YAP_UserCPred, YAP_UserCPred,
-                            YAP_Arity, YAP_Arity);
+                                  YAP_Arity, YAP_Arity);
 }
 
 YAPAtomTerm::YAPAtomTerm(char *s) { // build string
@@ -445,8 +445,6 @@ YAPQuery::YAPQuery(YAPPredicate p, YAPTerm ts[]) : YAPPredicate(p.ap) {
 YAPListTerm YAPQuery::namedVars() {
   CACHE_REGS
   Term o = vnames.term();
-  Yap_DebugPlWrite(o);
-  printf("<<<<<<<<<<<<<<<<-------------------------\n");
   return o; // should be o
 }
 
@@ -454,9 +452,6 @@ bool YAPQuery::next() {
   CACHE_REGS
   int result;
 
-  Yap_DebugPlWrite(vnames.term());
-  fprintf(stderr, "++++++++++++++\n");
-
   BACKUP_MACHINE_REGS();
   if (q_open != 1)
     return false;
@@ -464,17 +459,15 @@ bool YAPQuery::next() {
     return false;
   // don't forget, on success these guys must create slots
   if (this->q_state == 0) {
-    fprintf(stderr, "+++++ ap=%p +++++++++\n", ap);
-    Yap_DebugPlWrite(Yap_GetFromSlot(q_g));
-    fprintf(stderr, "+++++ ap +++++++++\n");
     result = (bool)YAP_EnterGoal((YAP_PredEntryPtr)ap, q_g, &q_h);
-    Yap_DebugPlWrite(Yap_GetFromSlot(q_g));
-    fprintf(stderr, "+++++ ap=%d +++++++++\n", result);
   } else {
     LOCAL_AllowRestart = q_open;
     result = (bool)YAP_RetryGoal(&q_h);
   }
   q_state = 1;
+  if (Yap_GetException()) {
+    throw(YAPError(SYSTEM_ERROR_INTERNAL));
+  }
   if (!result) {
     YAP_LeaveGoal(FALSE, &q_h);
     q_open = 0;
@@ -495,6 +488,17 @@ void YAPQuery::cut() {
   RECOVER_MACHINE_REGS();
 }
 
+bool YAPQuery::deterministic() {
+  CACHE_REGS
+
+  BACKUP_MACHINE_REGS();
+  if (q_open != 1 || q_state == 0)
+    return false;
+  choiceptr myB = (choiceptr)(LCL0 - q_h.b);
+  return (B >= myB);
+  RECOVER_MACHINE_REGS();
+}
+
 void YAPQuery::close() {
   CACHE_REGS
 
@@ -595,12 +599,7 @@ YAPEngine::YAPEngine(char *savedState, size_t stackSize, size_t trailSize,
   init_args.YapPrologBootFile = bootFile;
   init_args.YapPrologGoal = goal;
   init_args.YapPrologTopLevelGoal = topLevel;
-  init_args.HaltAfter
-	  
-	  
-	  
-	  
-	  = script;
+  init_args.HaltAfterConsult = script;
   init_args.FastBoot = fastBoot;
   yerror = YAPError();
   delYAPCallback();
diff --git a/CXX/yapi.hh b/CXX/yapi.hh
index 86ffca0f3..cacdb736b 100644
--- a/CXX/yapi.hh
+++ b/CXX/yapi.hh
@@ -1,7 +1,7 @@
 
 #define YAP_CPP_INTERFACE 1
 
-
+#include <gmpxx.h>
 
 //! @{
 
@@ -23,9 +23,7 @@
 #include <string>
 
 // Bad export from Python
-#ifdef HAVE_STAT
-#undef HAVE_STAT
-#endif
+
 #include <config.h>
 
 extern "C" {
diff --git a/CXX/yapq.hh b/CXX/yapq.hh
index 75065dc90..6a81e291a 100644
--- a/CXX/yapq.hh
+++ b/CXX/yapq.hh
@@ -43,7 +43,7 @@ public:
   inline YAPQuery(const char *s): YAPPredicate(s, t, names)
   {
     vnames = YAPListTerm( names );
-       
+
     initQuery( t );
   };
 
@@ -58,6 +58,9 @@ public:
   /// ask for the next solution of the current query
   /// same call for every solution
   bool next();
+  /// does this query have open choice-points?
+  /// or is it deterministic?
+  bool deterministic();
   /// represent the top-goal
   const char *text();
   /// remove alternatives in the current search space, and finish the current query
diff --git a/CXX/yapt.hh b/CXX/yapt.hh
index 07f551e0d..fb9cfcdb8 100644
--- a/CXX/yapt.hh
+++ b/CXX/yapt.hh
@@ -1,9 +1,13 @@
+#ifndef __unix__
+#define X_API
+#endif
+
 #ifndef YAPT_HH
 #define YAPT_HH 1
 
 class YAPAtomTerm;
 
-extern "C" Term X_API YAP_ReadBuffer(const char *s, Term *tp);
+extern "C" X_API Term  YAP_ReadBuffer(const char *s, Term *tp);
 
 /**
  * @brief Generic Prolog Term
diff --git a/H/TermExt.h b/H/TermExt.h
index be4378f33..bc4dd8177 100755
--- a/H/TermExt.h
+++ b/H/TermExt.h
@@ -337,9 +337,7 @@ INLINE_ONLY inline EXTERN int IsStringTerm(Term t) {
 
 #include <stdio.h>
 
-#if defined(__cplusplus)
-#include <gmpxx.h>
-#elif !defined(__GMP_H__)
+#if !defined(__cplusplus)
 #include <gmp.h>
 #endif
 
diff --git a/H/Yap.h b/H/Yap.h
index 37daeb73b..d53ea36b7 100755
--- a/H/Yap.h
+++ b/H/Yap.h
@@ -47,9 +47,6 @@
 #endif /* THREADS && (YAPOR_COW || YAPOR_SBA || YAPOR_COPY) */
 
 // Bad export from Python
-#ifdef HAVE_STAT
-#undef HAVE_STAT
-#endif
 #include "config.h"
 
 #ifndef COROUTINING
diff --git a/cmake/python.cmake b/cmake/python.cmake
new file mode 100644
index 000000000..018fd332a
--- /dev/null
+++ b/cmake/python.cmake
@@ -0,0 +1,26 @@
+
+
+#BREW install for Python3
+
+
+if (APPLE)
+foreach (i 3.6 3.5 3.4 3.3 3.2 3.1 3.0)
+  set (PYTHON_INCLUDE_DIRS /usr/local/Frameworks/Python.framework/Versions/${i}/Headers)
+  message("Trying Python ${i}")
+  if (EXISTS ${PYTHON_INCLUDE_DIRS})
+      set (PYTHON_EXECUTABLE /usr/local/bin/python${i} CACHE FILEPATH  "Path to a program" FORCE )
+    set (PYTHON_INCLUDE_DIR /usr/local/Frameworks/Python.framework/Versions/${i}/include/python${i}m
+    CACHE PATH "Path to a file." FORCE   )
+    set (PYTHON_LIBRARY /usr/local/Frameworks/Python.framework/Versions/${i}/lib/libpython${i}.dylib
+    CACHE FILEPATH  "Path to a library" FORCE )
+    break()
+  endif()
+endforeach()
+endif()
+
+find_package(PythonInterp)
+find_package(PythonLibs)
+
+ macro_log_feature (PYTHONLIBS_FOUND "Python"
+   "Use Python System"
+   "http://www.python.org" FALSE)
diff --git a/console/yap.c b/console/yap.c
index b2bc82f6e..a19b3c93c 100755
--- a/console/yap.c
+++ b/console/yap.c
@@ -146,6 +146,7 @@ int main(int argc, char **argv)
       YAP_RunGoalOnce(t_goal);
     }
   }
+
   YAP_Reset(YAP_FULL_RESET);
   /* End preprocessor code */
 
diff --git a/include/YapDefs.h b/include/YapDefs.h
index c874e814c..7301cfb27 100755
--- a/include/YapDefs.h
+++ b/include/YapDefs.h
@@ -240,9 +240,9 @@ typedef struct yap_boot_params {
   /* if NON-NULL, a path to extend file-search-path   */
   char *YapPrologAddPath;
   /* if previous NON-NULL and TRUE, halt after consulting that file  */
-  int HaltAfterConsult;
+  bool HaltAfterConsult;
   /* ignore .yaprc, .prolog.ini, etc. files.  */
-  int FastBoot;
+  bool FastBoot;
   /* the next field only interest YAPTAB */
   /* if NON-0, maximum size for Table Space */
   unsigned long int MaxTableSpaceSize;
diff --git a/packages/myddas/pl/CMakeLists.txt b/packages/myddas/pl/CMakeLists.txt
index 3f016f1c9..f94156b6d 100644
--- a/packages/myddas/pl/CMakeLists.txt
+++ b/packages/myddas/pl/CMakeLists.txt
@@ -31,15 +31,15 @@ ENDIF(MSVC)
     set_source_files_properties(${outfile} PROPERTIES GENERATED TRUE)
 endfunction()
 
-
-Add_custom_target (plmyddas ALL DEPENDS ${MYDDAS_YPP} ) # WORKING_DIRECTORY ${CMAKE_BINARY_DIR} )
-
 foreach(file ${MYDDAS_YPP})
    cpp_compile( MYDDAS_YAP ${file})
     #message("outfiles=${MYDDAS_YAP}\n")
   endforeach()
 
 
+
+  Add_custom_target (plmyddas ALL DEPENDS ${MYDDAS_YPP} ${MYDDAS_YAP} ) # WORKING_DIRECTORY ${CMAKE_BINARY_DIR} )
+
 install(FILES ${MYDDAS_YAP}
   DESTINATION ${libpl}
-)	
+)
diff --git a/packages/python/CMakeLists.txt b/packages/python/CMakeLists.txt
index 9d962b05c..41c9329cc 100644
--- a/packages/python/CMakeLists.txt
+++ b/packages/python/CMakeLists.txt
@@ -10,11 +10,6 @@ set (PYTHON_SOURCES
 #set(  PYTHON_LIBRARY /usr/local/opt/python/Frameworks/Python.framework/Versions/Current/lib/libpython2.7.dylib) #             - path to the python library
 #set(  PYTHON_INCLUDE_DIR /usr/local/opt/python/Frameworks/Python.framework/Versions/Current/include/python2.7 )  #      - path to where Python.h is found
 
-  macro_optional_find_package(PythonInterp ON)
-  macro_optional_find_package (PythonLibs ON)
-  macro_log_feature (PYTHONLIBS_FOUND "Python"
-    "Use Python System"
-    "http://www.python.org" FALSE)
 
 if (PYTHONLIBS_FOUND)         #   PYTHONLIBS_FOUND           - have the Python libs been found
   #   PYTHON_LIBRARIES           - path to the python library
@@ -45,7 +40,7 @@ if (PYTHONLIBS_FOUND)         #   PYTHONLIBS_FOUND           - have the Python l
   add_library (libpython SHARED ${PYTHON_SOURCES})
 
   target_link_libraries(libpython libYap ${PYTHON_LIBRARIES})
-  
+
 
   set_target_properties (libpython PROPERTIES PREFIX "")
 
diff --git a/packages/python/python.c b/packages/python/python.c
index 6751f072b..b80f78e19 100644
--- a/packages/python/python.c
+++ b/packages/python/python.c
@@ -136,7 +136,7 @@ static int copy_to_dictionary(PyObject *dict, term_t targ, term_t taux) {
       if (lhs == NULL) {
         return FALSE;
       }
-     if (!PL_get_arg(2, targ, tright)) {
+      if (!PL_get_arg(2, targ, tright)) {
         return FALSE;
       }
       rhs = term_to_python(tright);
@@ -438,8 +438,8 @@ static PyObject *bip_sum(term_t t) {
       return NULL;
     }
     Py_INCREF(result);
-  }
 #endif
+  }
 
 #ifndef SLOW_SUM
 /* Fast addition by keeping temporary sums in C instead of new Python objects.
@@ -521,14 +521,17 @@ to the more general routine.
       if (PyInt_CheckExact(item)) {
         PyFPE_START_PROTECT("add", Py_DECREF(item); Py_DECREF(iter); return 0)
             f_result += (double)PyInt_AS_LONG(item);
+        PyFPE_END_PROTECT(f_result) Py_DECREF(item);
+        continue;
+      }
 #else
       if (PyLong_CheckExact(item)) {
         PyFPE_START_PROTECT("add", Py_DECREF(item); Py_DECREF(iter); return 0)
             f_result += PyLong_AsDouble(item);
-#endif
         PyFPE_END_PROTECT(f_result) Py_DECREF(item);
         continue;
       }
+#endif
       result = PyFloat_FromDouble(f_result);
       temp = PyNumber_Add(result, item);
       Py_DECREF(result);
@@ -539,8 +542,8 @@ to the more general routine.
         return NULL;
       }
     }
-  }
 #endif
+  }
 
   for (;;) {
     item = PyIter_Next(iter);
@@ -667,7 +670,7 @@ static PyObject *bip_range(term_t t) {
 #if PY_MAJOR_VERSION < 3
     PyObject *w = PyInt_FromLong(ilow);
 #else
-      PyObject *w = PyLong_FromLong(ilow);
+    PyObject *w = PyLong_FromLong(ilow);
 #endif
     if (w == NULL) {
       Py_DECREF(v);
@@ -762,7 +765,7 @@ static PyObject *term_to_python(term_t t) {
 #if PY_MAJOR_VERSION < 3
     return PyInt_FromLong(j);
 #else
-      return PyLong_FromLong(j);
+    return PyLong_FromLong(j);
 #endif
   }
   case PL_FLOAT: {
@@ -996,7 +999,7 @@ static PyObject *term_to_python(term_t t) {
 #if PY_MAJOR_VERSION < 3
         return PyNumber_Divide(lhs, rhs);
 #else
-          return PyNumber_TrueDivide(lhs, rhs);
+        return PyNumber_TrueDivide(lhs, rhs);
 #endif
       } else if (fun == FUNCTOR_sqbrackets2) {
         //
@@ -1360,9 +1363,9 @@ static foreign_t python_to_term(PyObject *pVal, term_t t) {
     wchar_t *ptr = malloc(sizeof(wchar_t) * sz);
     sz = PyUnicode_AsWideChar((PyUnicodeObject *)pVal, ptr, sz - 1);
 #else
-      Py_ssize_t sz = PyUnicode_GetLength(pVal) + 1;
-      wchar_t *ptr = malloc(sizeof(wchar_t) * sz);
-      sz = PyUnicode_AsWideChar(pVal, ptr, sz);
+    Py_ssize_t sz = PyUnicode_GetLength(pVal) + 1;
+    wchar_t *ptr = malloc(sizeof(wchar_t) * sz);
+    sz = PyUnicode_AsWideChar(pVal, ptr, sz);
 #endif
     tmp_atom = PL_new_atom_wchars(sz, ptr);
     free(ptr);
@@ -1430,24 +1433,22 @@ static foreign_t python_to_term(PyObject *pVal, term_t t) {
     PL_cons_functor(to, FUNCTOR_curly1, to);
     return PL_unify(t, to);
   } else {
-    char *s;
     PyObject *pValR = PyObject_Repr(pVal);
     if (pValR == NULL)
       return address_to_term(pVal, t);
-#if PY_MAJOR_VERSION < 3
     Py_ssize_t sz = PyUnicode_GetSize(pValR) + 1;
+#if PY_MAJOR_VERSION < 3
     s = malloc(sizeof(char) * sz);
     PyObject *us = PyUnicode_EncodeUTF8((const Py_UNICODE *)pValR, sz, NULL);
-    free(s);
     PyString_AsStringAndSize(us, &s, &sz);
+    foreign_t rc = repr_term(s, sz, t);
+    free(s);
+    return rc;
 #else
-      Py_ssize_t sz = PyUnicode_GetLength(pVal) + 1;
-      s = malloc(sizeof(char) * sz);
-      PyObject *obj = PyUnicode_AsUTF8Char(pVal, ptr, sz);
-      PyString_AsStringAndSize(obj, &s, &sz);
-#endif
-
+    // new interface
+    char *s = PyUnicode_AsUTF8AndSize(pVal, &sz);
     return repr_term(s, sz, t);
+#endif
   }
 }
 
@@ -1485,15 +1486,14 @@ static int python_import(term_t mname, term_t mod) {
     strcat(str, ".");
     strcat(str, s2);
     s = str;
-  } else if (!PL_get_nchars(mname, &len, &s, 
-			    CVT_ALL | CVT_EXCEPTION)) {
+  } else if (!PL_get_nchars(mname, &len, &s, CVT_ALL | CVT_EXCEPTION)) {
     return FALSE;
   }
 #if PY_MAJOR_VERSION < 3
   pName = PyString_FromString(s);
 #else
-printf("Module=%s\n",s);
-    pName = PyUnicode_FromString(s);
+  printf("Module=%s\n", s);
+  pName = PyUnicode_FromString(s);
 #endif
   if (pName == NULL) {
     return FALSE;
@@ -1527,7 +1527,7 @@ static foreign_t python_f(term_t tmod, term_t fname, term_t tf) {
 #if PY_MAJOR_VERSION < 3
     pName = PyString_FromString(s);
 #else
-      pName = PyUnicode_FromString(s);
+    pName = PyUnicode_FromString(s);
 #endif
     if (pName == NULL) {
       return FALSE;
@@ -1544,7 +1544,7 @@ static foreign_t python_f(term_t tmod, term_t fname, term_t tf) {
   if (pF == NULL || !PyCallable_Check(pF)) {
     return FALSE;
   }
-printf("Module=%s ok\n",s);
+  printf("Module=%s ok\n", s);
   return python_to_ptr(pF, tf);
 }
 
@@ -1598,7 +1598,11 @@ static foreign_t python_index(term_t tobj, term_t tindex, term_t val) {
   i = term_to_python(tindex);
   if (i == NULL)
     return false;
+#if PY_MAJOR_VERSION < 3
   f = PyObject_CallMethodObjArgs(o, PyString_FromString("getitem"), i);
+#else
+  f = PyObject_CallMethodObjArgs(o, PyUnicode_FromString("getitem"), i);
+#endif
   return python_to_ptr(f, val);
 }
 
@@ -1611,81 +1615,78 @@ static foreign_t python_is(term_t tobj, term_t tf) {
 
   return python_to_ptr(o, tf);
 }
-    
-    static foreign_t python_assign_item(term_t parent, term_t indx, term_t tobj) {
-      PyObject *pF, *pI;
-      
-      PyObject *p;
-      
-      // get Scope ...
-      pI = term_to_python(indx);
-      // got Scope.Exp
-      // get Scope ...
-      p = term_to_python(parent);
-      // Exp
-      // get Scope ...
-      pF = term_to_python(parent);
-      // Exp
-      if (!pI || !p) {
-        return false;
-      } else if (PyObject_SetItem(p, pI,pF)) {
-        PyErr_Print();
-        return FALSE;
-      }
-      Py_DecRef(pI);
-      Py_DecRef(p);
-      
-      return true;
-    }
-    
-    static foreign_t python_item(term_t parent, term_t indx, term_t tobj) {
-      PyObject *pF, *pI;
-      
-      PyObject *p;
-      
-      // get Scope ...
-      pI = term_to_python(indx);
-      // got Scope.Exp
-      // get Scope ...
-      p = term_to_python(parent);
-      // Exp
-      if (!pI || !p) {
-        return false;
-      } else if ((pF =PyObject_GetItem(p, pI)) == NULL) {
-        PyErr_Print();
-        return FALSE;
-      }
-      Py_DecRef(pI);
-      Py_DecRef(p);
-      
-      return address_to_term(pF, tobj);
-    }
-    
-    
-    static foreign_t python_slice(term_t parent, term_t indx, term_t tobj) {
-      PyObject *pF, *pI;
-      
-      PyObject *p;
-      
-      // get Scope ...
-      pI = term_to_python(indx);
-      // got Scope.Exp
-      // get Scope ...
-      p = term_to_python(parent);
-      // Exp
-      if (!pI || !p) {
-        return false;
-      } else if ((pF =PySequence_GetSlice(p, 0, 0)) == NULL) {
-        PyErr_Print();
-        return FALSE;
-      }
-      Py_DecRef(pI);
-      Py_DecRef(p);
-      
-      return address_to_term(pF, tobj);
-    }
-    
-    
+
+static foreign_t python_assign_item(term_t parent, term_t indx, term_t tobj) {
+  PyObject *pF, *pI;
+
+  PyObject *p;
+
+  // get Scope ...
+  pI = term_to_python(indx);
+  // got Scope.Exp
+  // get Scope ...
+  p = term_to_python(parent);
+  // Exp
+  // get Scope ...
+  pF = term_to_python(parent);
+  // Exp
+  if (!pI || !p) {
+    return false;
+  } else if (PyObject_SetItem(p, pI, pF)) {
+    PyErr_Print();
+    return FALSE;
+  }
+  Py_DecRef(pI);
+  Py_DecRef(p);
+
+  return true;
+}
+
+static foreign_t python_item(term_t parent, term_t indx, term_t tobj) {
+  PyObject *pF, *pI;
+
+  PyObject *p;
+
+  // get Scope ...
+  pI = term_to_python(indx);
+  // got Scope.Exp
+  // get Scope ...
+  p = term_to_python(parent);
+  // Exp
+  if (!pI || !p) {
+    return false;
+  } else if ((pF = PyObject_GetItem(p, pI)) == NULL) {
+    PyErr_Print();
+    return FALSE;
+  }
+  Py_DecRef(pI);
+  Py_DecRef(p);
+
+  return address_to_term(pF, tobj);
+}
+
+static foreign_t python_slice(term_t parent, term_t indx, term_t tobj) {
+  PyObject *pF, *pI;
+
+  PyObject *p;
+
+  // get Scope ...
+  pI = term_to_python(indx);
+  // got Scope.Exp
+  // get Scope ...
+  p = term_to_python(parent);
+  // Exp
+  if (!pI || !p) {
+    return false;
+  } else if ((pF = PySequence_GetSlice(p, 0, 0)) == NULL) {
+    PyErr_Print();
+    return FALSE;
+  }
+  Py_DecRef(pI);
+  Py_DecRef(p);
+
+  return address_to_term(pF, tobj);
+}
 
 static foreign_t python_apply(term_t tin, term_t targs, term_t keywds,
                               term_t tf) {
@@ -1819,7 +1820,7 @@ static foreign_t python_builtin_eval(term_t caller, term_t dict, term_t out) {
       return false;
     }
   }
-  pOut = PyObject_CallObject((PyObject *)&PyFile_Type, pArgs);
+  pOut = PyObject_CallObject(pI, pArgs);
   Py_DECREF(pArgs);
   Py_DECREF(pI);
   if (pOut == NULL) {
@@ -1978,7 +1979,7 @@ static foreign_t array_to_python_list(term_t addr, term_t type, term_t szt,
     }
   }
   if (PL_is_variable(py)) {
-    return python_to_ptr( list, py);
+    return python_to_ptr(list, py);
   }
   return assign_to_symbol(py, list);
 }
@@ -2010,7 +2011,11 @@ static foreign_t array_to_python_tuple(term_t addr, term_t type, term_t szt,
     int32_t *v = (int32_t *)src;
     PyObject *x;
     for (i = 0; i < sz; i++) {
+#if PY_MAJOR_VERSION < 3
       x = PyInt_FromLong(v[i]);
+#else
+      x = PyLong_FromLong(v[i]);
+#endif
       if (PyTuple_SetItem(list, i, x)) {
         PyErr_Print();
         return FALSE;
@@ -2065,8 +2070,15 @@ static foreign_t python_run_file(term_t file) {
   char si[256];
   s = si;
   if (PL_get_nchars(file, &len, &s, CVT_ALL | CVT_EXCEPTION)) {
+#if PY_MAJOR_VERSION < 3
     PyObject *PyFileObject = PyFile_FromString(si, "r");
     PyRun_SimpleFileEx(PyFile_AsFile(PyFileObject), "test.py", 1);
+#else
+    FILE *f = fopen(s, "r");
+    if (f == NULL)
+      return false;
+    PyRun_SimpleFileEx(f, s, 1);
+#endif
     return TRUE;
   }
   return false;
@@ -2095,7 +2107,12 @@ static foreign_t python_run_script(term_t cmd, term_t fun) {
       (s = sf) != NULL &&
       PL_get_nchars(fun, &len1, &s, CVT_ALL | CVT_EXCEPTION)) {
 
+#if PY_MAJOR_VERSION < 3
     pName = PyString_FromString("rbm");
+#else
+    // asssumes UTF-8
+    pName = PyUnicode_FromString("rbm");
+#endif
     /* Error checking of pName left out */
 
     pModule = PyImport_Import(pName);
@@ -2108,7 +2125,6 @@ static foreign_t python_run_script(term_t cmd, term_t fun) {
       if (pFunc && PyCallable_Check(pFunc)) {
         pValue = PyObject_CallObject(pFunc, pArgs);
         if (pValue != NULL) {
-          printf("Result of call: %ld\n", PyInt_AsLong(pValue));
           Py_DECREF(pValue);
         } else {
           Py_DECREF(pFunc);
@@ -2143,7 +2159,12 @@ static foreign_t init_python(void) {
   char **argv;
   term_t t = PL_new_term_ref();
   YAP_Argv(&argv);
+#if PY_MAJOR_VERSION < 3
   Py_SetProgramName(argv[0]);
+#else
+  wchar_t *buf = Py_DecodeLocale(argv[0], NULL);
+  Py_SetProgramName(buf);
+#endif
   Py_Initialize();
   py_Main = PyImport_AddModule("__main__");
   py_Builtin = PyImport_AddModule("__builtin__");
@@ -2227,6 +2248,3 @@ install_t install_libpython(void) {
   PL_register_foreign("python_builtin_eval", 3, python_builtin_eval, 0);
   PL_register_foreign("python_builtin", 1, python_builtin, 0);
 }
-
-
-  
diff --git a/packages/swig/python/yapex.py b/packages/swig/python/yapex.py
new file mode 100644
index 000000000..5fb97776a
--- /dev/null
+++ b/packages/swig/python/yapex.py
@@ -0,0 +1,50 @@
+# python commands
+
+import sys
+import yap
+
+#
+# initialize engine
+engine = yap.YAPEngine();
+# engine = yap.YAPEngine(yap.YAPParams());
+
+def query( s ):
+    q = engine.query(s)
+    while q.next():
+        vs = q.namedVars()
+        if vs.length() == 0:
+            print( "yes" )
+            return
+        else:
+            while vs.length() > 0:
+                eq = vs.car()
+                print( eq.getArg(1).text() + " = " + eq.getArg(2).text() )
+                vs = vs.cdr()
+            if q.deterministic():
+                return
+            s = input("next: ?")
+            if s.find(';') != 0 :
+                return
+    print( "no more answers" )
+    return
+
+def live():
+    loop = True
+    while loop:
+        try:
+            s = input("?- ")
+            query( s )
+        except SyntaxError as err:
+            print("Syntax Error error: {0}".format(err))
+        except EOFError:
+            return
+        except RuntimeError as err:
+            print("YAP Execution Error: {0}".format(err))
+        except ValueError:
+            print("Could not convert data to an integer.")
+        except:
+            print("Unexpected error:", sys.exc_info()[0])
+            raise
+
+
+live()
diff --git a/pl/load_foreign.yap b/pl/load_foreign.yap
index f9425e3b8..f5e4fd99d 100644
--- a/pl/load_foreign.yap
+++ b/pl/load_foreign.yap
@@ -41,7 +41,7 @@ specifying the object files to load,  _Libs_ is a list (possibly
 empty) of libraries to be passed to the unix loader (`ld`) and
 InitRoutine is the name of the C routine (to be called after the files
 are loaded) to perform the necessary declarations to YAP of the
-predicates defined in the files. 
+predicates defined in the files.
 
 YAP will search for  _ObjectFiles_ in the current directory first. If
 it cannot find them it will search for the files using the environment
@@ -59,7 +59,7 @@ load_foreign_files(Objs,Libs,Entry) :-
     '$check_objs_for_load_foreign_files'(Objs,NewObjs,load_foreign_files(Objs,Libs,Entry)),
     '$check_libs_for_load_foreign_files'(Libs,NewLibs,load_foreign_files(Objs,Libs,Entry)),
     '$check_entry_for_load_foreign_files'(Entry,load_foreign_files(Objs,Libs,Entry)),
-    ( 
+    (
 	recordzifnot( '$foreign', M:'$foreign'(Objs,Libs,Entry), _)
 	->
 	'$load_foreign_files'(NewObjs,NewLibs,Entry),
@@ -71,9 +71,9 @@ load_foreign_files(Objs,Libs,Entry) :-
 	    true
         )
 	;
-	true 
+	true
    ),
-   !. 
+   !.
 
 /** @pred load_absolute_foreign_files( _Files_, _Libs_, _InitRoutine_)
 
@@ -82,7 +82,7 @@ Loads object files produced by the C compiler. It is useful when no search shoul
 */
 load_absolute_foreign_files(Objs,Libs,Entry) :-
     source_module(M),
-    ( 
+    (
 	recordzifnot( '$foreign', M:'$foreign'(Objs,Libs,Entry), _)
 	->
 	'$load_foreign_files'(Objs,Libs,Entry),
@@ -94,7 +94,7 @@ load_absolute_foreign_files(Objs,Libs,Entry) :-
 	    true
         )
 	;
-	true 
+	true
    ),
    !.
 
@@ -176,7 +176,7 @@ On errors, an exception `shared_object`( _Action_,
  _Message_) is raised.  _Message_ is the return value from
 dlerror().
 
- 
+
 */
 open_shared_object(File, Handle) :-
 	open_shared_object(File, [], Handle).
@@ -185,15 +185,15 @@ open_shared_object(File, Handle) :-
 
 As `open_shared_object/2`, but allows for additional flags to
 be passed.  _Options_ is a list of atoms. `now` implies the
-symbols are 
+symbols are
 resolved immediately rather than lazily (default). `global` implies
 symbols of the loaded object are visible while loading other shared
 objects (by default they are local). Note that these flags may not
 be supported by your operating system. Check the documentation of
 `dlopen()` or equivalent on your operating system. Unsupported
-flags  are silently ignored. 
+flags  are silently ignored.
+
 
- 
 */
 open_shared_object(File, Opts, Handle) :-
 	'$open_shared_opts'(Opts, open_shared_object(File, Opts, Handle), OptsI),
@@ -209,7 +209,7 @@ open_shared_object(File, Opts, Handle) :-
 	'$open_shared_opts'(Opts, G, V0),
 	'$open_shared_opt'(Opt, G, OptV),
 	V0 is V \/ OptV.
-	
+
 '$open_shared_opt'(Opt, G, _) :-
 	var(Opt), !,
 	'$do_error'(instantiation_error,G).
@@ -217,7 +217,7 @@ open_shared_object(File, Opts, Handle) :-
 '$open_shared_opt'(global, __, 2) :- !.
 '$open_shared_opt'(Opt, Goal, _) :-
 	'$do_error'(domain_error(open_shared_object_option,Opt),Goal).
-	
+
 /** @pred call_shared_object_function(+ _Handle_, + _Function_)
 
 Call the named function in the loaded shared library. The function is
@@ -233,3 +233,11 @@ call_shared_object_function( Handle, Function) :-
     ignore( recordzifnot( '$foreign', M:'$swi_foreign'( Handle, Function ), _) ).
 %% @}
 
+/** @pred $slave is det
+
+Called at boot-time when Prolog is run from another language (eg, Java, Python, Android)
+*/
+
+'$slave' :-
+    getenv( '__PYVENV_LAUNCHER__', _ ),
+    use_module( library(python) ).