diff --git a/ortools/algorithms/set_cover_heuristics.cc b/ortools/algorithms/set_cover_heuristics.cc
index 4208c90e17..dc6377b893 100644
--- a/ortools/algorithms/set_cover_heuristics.cc
+++ b/ortools/algorithms/set_cover_heuristics.cc
@@ -122,8 +122,8 @@ bool GreedySolutionGenerator::NextSolution(
   return NextSolution(focus, inv_->model()->subset_costs());
 }
 
-bool GreedySolutionGenerator::NextSolution(
-    const std::vector<SubsetIndex>& focus, const SubsetCostVector& costs) {
+bool GreedySolutionGenerator::NextSolution(absl::Span<const SubsetIndex> focus,
+                                           const SubsetCostVector& costs) {
   DCHECK(inv_->CheckConsistency());
   inv_->ClearTrace();
   SubsetCostVector elements_per_cost(costs.size(), 0.0);
diff --git a/ortools/algorithms/set_cover_heuristics.h b/ortools/algorithms/set_cover_heuristics.h
index 154724cf61..c8440bf64e 100644
--- a/ortools/algorithms/set_cover_heuristics.h
+++ b/ortools/algorithms/set_cover_heuristics.h
@@ -174,7 +174,7 @@ class GreedySolutionGenerator {
   bool NextSolution(const std::vector<SubsetIndex>& focus);
 
   // Same with a different set of costs.
-  bool NextSolution(const std::vector<SubsetIndex>& focus,
+  bool NextSolution(absl::Span<const SubsetIndex> focus,
                     const SubsetCostVector& costs);
 
  private:
diff --git a/ortools/glop/lu_factorization.cc b/ortools/glop/lu_factorization.cc
index 8deed0b61c..e50e9f9d3d 100644
--- a/ortools/glop/lu_factorization.cc
+++ b/ortools/glop/lu_factorization.cc
@@ -133,7 +133,7 @@ namespace {
 // norm of the given column, otherwise do the same with a sparse version. In
 // both cases column is cleared.
 Fractional ComputeSquaredNormAndResetToZero(
-    const std::vector<RowIndex>& non_zeros, absl::Span<Fractional> column) {
+    absl::Span<const RowIndex> non_zeros, absl::Span<Fractional> column) {
   Fractional sum = 0.0;
   if (non_zeros.empty()) {
     sum = SquaredNormAndResetToZero(column);
diff --git a/ortools/linear_solver/model_exporter.cc b/ortools/linear_solver/model_exporter.cc
index 51d75611d6..cdccf8b241 100644
--- a/ortools/linear_solver/model_exporter.cc
+++ b/ortools/linear_solver/model_exporter.cc
@@ -149,11 +149,11 @@ class MPModelProtoExporter {
 
   // Appends a pair name, value to "output", formatted to comply with the MPS
   // standard.
-  void AppendMpsPair(const std::string& name, double value,
+  void AppendMpsPair(absl::string_view name, double value,
                      std::string* output) const;
 
   // Appends the head of a line, consisting of an id and a name to output.
-  void AppendMpsLineHeader(const std::string& id, const std::string& name,
+  void AppendMpsLineHeader(absl::string_view id, absl::string_view name,
                            std::string* output) const;
 
   // Same as AppendMpsLineHeader. Appends an extra new-line at the end the
@@ -674,13 +674,13 @@ bool MPModelProtoExporter::ExportModelAsLpFormat(
   return true;
 }
 
-void MPModelProtoExporter::AppendMpsPair(const std::string& name, double value,
+void MPModelProtoExporter::AppendMpsPair(absl::string_view name, double value,
                                          std::string* output) const {
   absl::StrAppendFormat(output, *mps_format_, name, DoubleToString(value));
 }
 
-void MPModelProtoExporter::AppendMpsLineHeader(const std::string& id,
-                                               const std::string& name,
+void MPModelProtoExporter::AppendMpsLineHeader(absl::string_view id,
+                                               absl::string_view name,
                                                std::string* output) const {
   absl::StrAppendFormat(output, *mps_header_format_, id, name);
 }
diff --git a/ortools/linear_solver/python/model_builder.py b/ortools/linear_solver/python/model_builder.py
index bca0e6df2c..9d9dc8f7c6 100644
--- a/ortools/linear_solver/python/model_builder.py
+++ b/ortools/linear_solver/python/model_builder.py
@@ -1599,11 +1599,31 @@ def import_from_mps_file(self, mps_file: str) -> bool:
         return self.__helper.import_from_mps_file(mps_file)
 
     def import_from_lp_string(self, lp_string: str) -> bool:
-        """Reads a model from a LP string."""
+        """Reads a model from a LP string.
+
+        Note that this code is very limited, and will not support any real lp.
+        It is only intented to be use to parse test lp problems.
+
+        Args:
+          lp_string: The LP string to import.
+
+        Returns:
+          True if the import was successful.
+        """
         return self.__helper.import_from_lp_string(lp_string)
 
     def import_from_lp_file(self, lp_file: str) -> bool:
-        """Reads a model from a .lp file."""
+        """Reads a model from a .lp file.
+
+        Note that this code is very limited, and will not support any real lp.
+        It is only intented to be use to parse test lp problems.
+
+        Args:
+          lp_file: The LP file to import.
+
+        Returns:
+          True if the import was successful.
+        """
         return self.__helper.import_from_lp_file(lp_file)
 
     def import_from_proto_file(self, proto_file: str) -> bool: