From 937d021dfd42ba4e77f616663bca0748e21df6ac Mon Sep 17 00:00:00 2001
From: Laurent Perron <lperron@lperron-macbookpro2.roam.corp.google.com>
Date: Wed, 16 Mar 2016 13:34:47 +0100
Subject: [PATCH] polish support for python3

---
 makefiles/Makefile.python.mk                | 14 +++++++++++++-
 src/linear_solver/python/linear_solver.swig | 17 +++++++++++++----
 src/util/python/proto.swig                  | 11 +++++++++++
 3 files changed, 37 insertions(+), 5 deletions(-)

diff --git a/makefiles/Makefile.python.mk b/makefiles/Makefile.python.mk
index 708138a8ee..a7dbbdf5cd 100644
--- a/makefiles/Makefile.python.mk
+++ b/makefiles/Makefile.python.mk
@@ -2,9 +2,21 @@
 
 # Detect python3
 
+ifeq ("$(PYTHON_VERSION)","3.2")
+  PYTHON3 = true
+  SWIG_PYTHON3_FLAG=-py3 -DPY3
+endif
 ifeq ("$(PYTHON_VERSION)","3.3")
   PYTHON3 = true
-  SWIG_PYTHON3_FLAG=-py3
+  SWIG_PYTHON3_FLAG=-py3 -DPY3
+endif
+ifeq ("$(PYTHON_VERSION)","3.4")
+  PYTHON3 = true
+  SWIG_PYTHON3_FLAG=-py3 -DPY3
+endif
+ifeq ("$(PYTHON_VERSION)","3.5")
+  PYTHON3 = true
+  SWIG_PYTHON3_FLAG=-py3 -DPY3
 endif
 
 # Main target
diff --git a/src/linear_solver/python/linear_solver.swig b/src/linear_solver/python/linear_solver.swig
index 19dc641049..fcd6043296 100644
--- a/src/linear_solver/python/linear_solver.swig
+++ b/src/linear_solver/python/linear_solver.swig
@@ -47,6 +47,7 @@ namespace operations_research {
 
 %pythoncode {
 import numbers
+import sys
 from ortools.linear_solver.linear_solver_natural_api import OFFSET_KEY
 from ortools.linear_solver.linear_solver_natural_api import inf
 from ortools.linear_solver.linear_solver_natural_api import LinearExpr
@@ -121,8 +122,12 @@ from ortools.linear_solver.linear_solver_natural_api import VariableExpr
     else:
         coeffs = expr.GetCoeffs()
         objective.AddOffset(coeffs.pop(OFFSET_KEY, 0.0))
-        for v, c, in coeffs.iteritems():
-          objective.SetCoefficient(v, float(c))
+        if sys.version_info >= (3, 0):
+          for v, c, in list(coeffs.items()):
+            objective.SetCoefficient(v, float(c))
+        else:
+          for v, c, in coeffs.iteritems():
+            objective.SetCoefficient(v, float(c))
 
   def Maximize(self, expr):
     objective = self.Objective()
@@ -133,8 +138,12 @@ from ortools.linear_solver.linear_solver_natural_api import VariableExpr
     else:
         coeffs = expr.GetCoeffs()
         objective.AddOffset(coeffs.pop(OFFSET_KEY, 0.0))
-        for v, c, in coeffs.iteritems():
-          objective.SetCoefficient(v, float(c))
+        if sys.version_info >= (3, 0):
+          for v, c, in list(coeffs.items()):
+            objective.SetCoefficient(v, float(c))
+        else:
+          for v, c, in coeffs.iteritems():
+            objective.SetCoefficient(v, float(c))
   }  // %pythoncode
 }
 
diff --git a/src/util/python/proto.swig b/src/util/python/proto.swig
index b12fdea7e9..3453d0751a 100644
--- a/src/util/python/proto.swig
+++ b/src/util/python/proto.swig
@@ -58,9 +58,15 @@ namespace operations_research {
 %typemap(argout) CppType* const, CppType* {
   std::string encoded_protobuf;
   $1->SerializeToString(&encoded_protobuf);
+#if defined(PY3)
+  PyObject* const python_encoded_protobuf =
+      PyBytes_FromStringAndSize(encoded_protobuf.c_str(),
+                                encoded_protobuf.size());
+#else  // PY3
   PyObject* const python_encoded_protobuf =
       PyString_FromStringAndSize(encoded_protobuf.c_str(),
                                  encoded_protobuf.size());
+#endif  // PY3
   if (python_encoded_protobuf != nullptr) {
     PyObject* const result = PyObject_CallMethod(
         $input, const_cast<char*>("ParseFromString"),
@@ -79,8 +85,13 @@ namespace operations_research {
       if (clss != nullptr) {
         std::string encoded_protobuf;
         $1.SerializeToString(&encoded_protobuf);
+#if defined(PY3)
+        PyObject* const python_encoded_protobuf = PyBytes_FromStringAndSize(
+            encoded_protobuf.c_str(), encoded_protobuf.size());
+#else  // PY3
         PyObject* const python_encoded_protobuf = PyString_FromStringAndSize(
             encoded_protobuf.c_str(), encoded_protobuf.size());
+#endif  // PY3
         PyObject* const result = PyObject_CallMethod(
               clss, const_cast<char*>("FromString"),
               const_cast<char*>("(O)"),