diff --git a/examples/python/appointments.py b/examples/python/appointments.py
index 9f1fc56e9f..aede63f771 100644
--- a/examples/python/appointments.py
+++ b/examples/python/appointments.py
@@ -38,7 +38,7 @@ class AllSolutionCollector(cp_model.CpSolverSolutionCallback):
         self.__variables = variables
         self.__collect = []
 
-    def OnSolutionCallback(self):
+    def on_solution_callback(self):
         """Collect a new combination."""
         combination = [self.Value(v) for v in self.__variables]
         self.__collect.append(combination)
diff --git a/examples/python/balance_group_sat.py b/examples/python/balance_group_sat.py
index 7ac3e5ba39..6d43d69851 100644
--- a/examples/python/balance_group_sat.py
+++ b/examples/python/balance_group_sat.py
@@ -37,7 +37,7 @@ class SolutionPrinter(cp_model.CpSolverSolutionCallback):
         self.__all_items = all_items
         self.__item_in_group = item_in_group
 
-    def OnSolutionCallback(self):
+    def on_solution_callback(self):
         print('Solution %i' % self.__solution_count)
         self.__solution_count += 1
 
@@ -61,9 +61,6 @@ class SolutionPrinter(cp_model.CpSolverSolutionCallback):
                 print(' (%i, %i, %i)' % (item, value, color), end='')
             print(']')
 
-    def SolutionCount(self):
-        return self.__solution_count
-
 
 def main():
     # Data.
diff --git a/examples/python/flexible_job_shop_sat.py b/examples/python/flexible_job_shop_sat.py
index ae3ab4becb..87aa7319a7 100644
--- a/examples/python/flexible_job_shop_sat.py
+++ b/examples/python/flexible_job_shop_sat.py
@@ -10,6 +10,7 @@
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
+"""Solves a flexible jobshop problems with the CP-SAT solver."""
 
 from __future__ import print_function
 
@@ -24,149 +25,156 @@ class SolutionPrinter(cp_model.CpSolverSolutionCallback):
         cp_model.CpSolverSolutionCallback.__init__(self)
         self.__solution_count = 0
 
-    def OnSolutionCallback(self):
+    def on_solution_callback(self):
+        """Called at each new solution."""
         print('Solution %i, time = %f s, objective = %i' %
               (self.__solution_count, self.WallTime(), self.ObjectiveValue()))
         self.__solution_count += 1
 
 
-# Data part.
-jobs = [[[(3, 0), (1, 1), (5, 2)], [(2, 0), (4, 1), (6, 2)],
-         [(2, 0), (3, 1), (1, 2)]],
-        [[(2, 0), (3, 1), (4, 2)], [(1, 0), (5, 1), (4, 2)],
-         [(2, 0), (1, 1), (4, 2)]],
-        [[(2, 0), (1, 1), (4, 2)], [(2, 0), (3, 1), (4, 2)],
-         [(3, 0), (1, 1), (5, 2)]]]
+def flexible_jobshop():
+    """Solve a small flexible jobshop problem."""
+    # Data part.
+    jobs = [[[(3, 0), (1, 1), (5, 2)], [(2, 0), (4, 1), (6, 2)],
+             [(2, 0), (3, 1), (1, 2)]],
+            [[(2, 0), (3, 1), (4, 2)], [(1, 0), (5, 1), (4, 2)],
+             [(2, 0), (1, 1), (4, 2)]],
+            [[(2, 0), (1, 1), (4, 2)], [(2, 0), (3, 1), (4, 2)],
+             [(3, 0), (1, 1), (5, 2)]]]
 
-num_jobs = len(jobs)
-all_jobs = range(num_jobs)
+    num_jobs = len(jobs)
+    all_jobs = range(num_jobs)
 
-num_machines = 3
-all_machines = range(num_machines)
+    num_machines = 3
+    all_machines = range(num_machines)
 
-# Model the flexible jobshop problem.
-model = cp_model.CpModel()
+    # Model the flexible jobshop problem.
+    model = cp_model.CpModel()
 
-horizon = 0
-for job in jobs:
-    for task in job:
-        max_task_duration = 0
-        for alternative in task:
-            max_task_duration = max(max_task_duration, alternative[0])
-        horizon += max_task_duration
+    horizon = 0
+    for job in jobs:
+        for task in job:
+            max_task_duration = 0
+            for alternative in task:
+                max_task_duration = max(max_task_duration, alternative[0])
+            horizon += max_task_duration
 
-print('Horizon = %i' % horizon)
+    print('Horizon = %i' % horizon)
 
-# Global storage of variables.
-intervals_per_resources = defaultdict(list)
-starts = {}  # indexed by (job_id, task_id).
-presences = {}  # indexed by (job_id, task_id, alt_id).
-job_ends = []
+    # Global storage of variables.
+    intervals_per_resources = defaultdict(list)
+    starts = {}  # indexed by (job_id, task_id).
+    presences = {}  # indexed by (job_id, task_id, alt_id).
+    job_ends = []
 
-# Scan the jobs and create the relevant variables and intervals.
-for job_id in all_jobs:
-    job = jobs[job_id]
-    num_tasks = len(job)
-    previous_end = None
-    for task_id in range(num_tasks):
-        task = job[task_id]
+    # Scan the jobs and create the relevant variables and intervals.
+    for job_id in all_jobs:
+        job = jobs[job_id]
+        num_tasks = len(job)
+        previous_end = None
+        for task_id in range(num_tasks):
+            task = job[task_id]
 
-        min_duration = task[0][0]
-        max_duration = task[0][0]
+            min_duration = task[0][0]
+            max_duration = task[0][0]
 
-        num_alternatives = len(task)
-        all_alternatives = range(num_alternatives)
+            num_alternatives = len(task)
+            all_alternatives = range(num_alternatives)
 
-        for alt_id in range(1, num_alternatives):
-            alt_duration = task[alt_id][0]
-            min_duration = min(min_duration, alt_duration)
-            max_duration = max(max_duration, alt_duration)
+            for alt_id in range(1, num_alternatives):
+                alt_duration = task[alt_id][0]
+                min_duration = min(min_duration, alt_duration)
+                max_duration = max(max_duration, alt_duration)
 
-        # Create main interval for the task.
-        suffix_name = '_j%i_t%i' % (job_id, task_id)
-        start = model.NewIntVar(0, horizon, 'start' + suffix_name)
-        duration = model.NewIntVar(min_duration, max_duration,
-                                   'duration' + suffix_name)
-        end = model.NewIntVar(0, horizon, 'end' + suffix_name)
-        interval = model.NewIntervalVar(start, duration, end,
-                                        'interval' + suffix_name)
+            # Create main interval for the task.
+            suffix_name = '_j%i_t%i' % (job_id, task_id)
+            start = model.NewIntVar(0, horizon, 'start' + suffix_name)
+            duration = model.NewIntVar(min_duration, max_duration,
+                                       'duration' + suffix_name)
+            end = model.NewIntVar(0, horizon, 'end' + suffix_name)
+            interval = model.NewIntervalVar(start, duration, end,
+                                            'interval' + suffix_name)
 
-        # Store the start for the solution.
-        starts[(job_id, task_id)] = start
+            # Store the start for the solution.
+            starts[(job_id, task_id)] = start
 
-        # Add precedence with previous task in the same job.
-        if previous_end:
-            model.Add(start >= previous_end)
-        previous_end = end
+            # Add precedence with previous task in the same job.
+            if previous_end:
+                model.Add(start >= previous_end)
+            previous_end = end
 
-        # Create alternative intervals.
-        if num_alternatives > 1:
-            l_presences = []
-            for alt_id in all_alternatives:
-                alt_suffix = '_j%i_t%i_a%i' % (job_id, task_id, alt_id)
-                l_presence = model.NewBoolVar('presence' + alt_suffix)
-                l_start = model.NewIntVar(0, horizon, 'start' + alt_suffix)
-                l_duration = task[alt_id][0]
-                l_end = model.NewIntVar(0, horizon, 'end' + alt_suffix)
-                l_interval = model.NewOptionalIntervalVar(
-                    l_start, l_duration, l_end, l_presence,
-                    'interval' + alt_suffix)
-                l_presences.append(l_presence)
+            # Create alternative intervals.
+            if num_alternatives > 1:
+                l_presences = []
+                for alt_id in all_alternatives:
+                    alt_suffix = '_j%i_t%i_a%i' % (job_id, task_id, alt_id)
+                    l_presence = model.NewBoolVar('presence' + alt_suffix)
+                    l_start = model.NewIntVar(0, horizon, 'start' + alt_suffix)
+                    l_duration = task[alt_id][0]
+                    l_end = model.NewIntVar(0, horizon, 'end' + alt_suffix)
+                    l_interval = model.NewOptionalIntervalVar(
+                        l_start, l_duration, l_end, l_presence,
+                        'interval' + alt_suffix)
+                    l_presences.append(l_presence)
 
-                # Link the master variables with the local ones.
-                model.Add(start == l_start).OnlyEnforceIf(l_presence)
-                model.Add(duration == l_duration).OnlyEnforceIf(l_presence)
-                model.Add(end == l_end).OnlyEnforceIf(l_presence)
+                    # Link the master variables with the local ones.
+                    model.Add(start == l_start).OnlyEnforceIf(l_presence)
+                    model.Add(duration == l_duration).OnlyEnforceIf(l_presence)
+                    model.Add(end == l_end).OnlyEnforceIf(l_presence)
 
-                # Add the local interval to the right machine.
-                intervals_per_resources[task[alt_id][1]].append(l_interval)
+                    # Add the local interval to the right machine.
+                    intervals_per_resources[task[alt_id][1]].append(l_interval)
 
-                # Store the presences for the solution.
-                presences[(job_id, task_id, alt_id)] = l_presence
+                    # Store the presences for the solution.
+                    presences[(job_id, task_id, alt_id)] = l_presence
 
-            # Select exactly one presence variable.
-            model.Add(sum(l_presences) == 1)
-        else:
-            intervals_per_resources[task[0][1]].append(interval)
-            presences[(job_id, task_id, 0)] = model.NewConstant(1)
+                # Select exactly one presence variable.
+                model.Add(sum(l_presences) == 1)
+            else:
+                intervals_per_resources[task[0][1]].append(interval)
+                presences[(job_id, task_id, 0)] = model.NewConstant(1)
 
-    job_ends.append(previous_end)
+        job_ends.append(previous_end)
 
-# Create machines constraints.
-for machine_id in all_machines:
-    intervals = intervals_per_resources[machine_id]
-    if len(intervals) > 1:
-        model.AddNoOverlap(intervals)
+    # Create machines constraints.
+    for machine_id in all_machines:
+        intervals = intervals_per_resources[machine_id]
+        if len(intervals) > 1:
+            model.AddNoOverlap(intervals)
 
-# Makespan objective
-makespan = model.NewIntVar(0, horizon, 'makespan')
-model.AddMaxEquality(makespan, job_ends)
-model.Minimize(makespan)
+    # Makespan objective
+    makespan = model.NewIntVar(0, horizon, 'makespan')
+    model.AddMaxEquality(makespan, job_ends)
+    model.Minimize(makespan)
 
-# Solve model.
-solver = cp_model.CpSolver()
-solution_printer = SolutionPrinter()
-status = solver.SolveWithSolutionCallback(model, solution_printer)
+    # Solve model.
+    solver = cp_model.CpSolver()
+    solution_printer = SolutionPrinter()
+    status = solver.SolveWithSolutionCallback(model, solution_printer)
 
-# Print final solution.
-for job_id in all_jobs:
-    print('Job %i:' % job_id)
-    for task_id in range(len(jobs[job_id])):
-        start_value = solver.Value(starts[(job_id, task_id)])
-        machine = -1
-        duration = -1
-        selected = -1
-        for alt_id in range(len(jobs[job_id][task_id])):
-            if solver.Value(presences[(job_id, task_id, alt_id)]):
-                duration = jobs[job_id][task_id][alt_id][0]
-                machine = jobs[job_id][task_id][alt_id][1]
-                selected = alt_id
-        print('  task_%i_%i starts at %i (alt %i, machine %i, duration %i)' %
-              (job_id, task_id, start_value, selected, machine, duration))
+    # Print final solution.
+    for job_id in all_jobs:
+        print('Job %i:' % job_id)
+        for task_id in range(len(jobs[job_id])):
+            start_value = solver.Value(starts[(job_id, task_id)])
+            machine = -1
+            duration = -1
+            selected = -1
+            for alt_id in range(len(jobs[job_id][task_id])):
+                if solver.Value(presences[(job_id, task_id, alt_id)]):
+                    duration = jobs[job_id][task_id][alt_id][0]
+                    machine = jobs[job_id][task_id][alt_id][1]
+                    selected = alt_id
+            print(
+                '  task_%i_%i starts at %i (alt %i, machine %i, duration %i)' %
+                (job_id, task_id, start_value, selected, machine, duration))
 
-print('Solve status: %s' % solver.StatusName(status))
-print('Optimal objective value: %i' % solver.ObjectiveValue())
-print('Statistics')
-print('  - conflicts : %i' % solver.NumConflicts())
-print('  - branches  : %i' % solver.NumBranches())
-print('  - wall time : %f s' % solver.WallTime())
+    print('Solve status: %s' % solver.StatusName(status))
+    print('Optimal objective value: %i' % solver.ObjectiveValue())
+    print('Statistics')
+    print('  - conflicts : %i' % solver.NumConflicts())
+    print('  - branches  : %i' % solver.NumBranches())
+    print('  - wall time : %f s' % solver.WallTime())
+
+
+flexible_jobshop()
diff --git a/examples/python/nqueens_sat.py b/examples/python/nqueens_sat.py
index 6e30efefe1..f459190d9d 100644
--- a/examples/python/nqueens_sat.py
+++ b/examples/python/nqueens_sat.py
@@ -26,10 +26,10 @@ class NQueenSolutionPrinter(cp_model.CpSolverSolutionCallback):
         self.__solution_count = 0
         self.__start_time = time.time()
 
-    def SolutionCount(self):
+    def solution_count(self):
         return self.__solution_count
 
-    def OnSolutionCallback(self):
+    def on_solution_callback(self):
         current_time = time.time()
         print('Solution %i, time = %f s' % (self.__solution_count,
                                             current_time - self.__start_time))
@@ -87,7 +87,7 @@ def main(board_size):
     print('  - conflicts       : %i' % solver.NumConflicts())
     print('  - branches        : %i' % solver.NumBranches())
     print('  - wall time       : %f ms' % solver.WallTime())
-    print('  - solutions found : %i' % solution_printer.SolutionCount())
+    print('  - solutions found : %i' % solution_printer.solution_count())
 
 
 # By default, solve the 8x8 problem.
diff --git a/examples/python/nurses_sat.py b/examples/python/nurses_sat.py
index ab2e5882b9..9f7308a6c0 100644
--- a/examples/python/nurses_sat.py
+++ b/examples/python/nurses_sat.py
@@ -28,7 +28,7 @@ class NursesPartialSolutionPrinter(cp_model.CpSolverSolutionCallback):
         self.__solutions = set(sols)
         self.__solution_count = 0
 
-    def OnSolutionCallback(self):
+    def on_solution_callback(self):
         self.__solution_count += 1
         if self.__solution_count in self.__solutions:
             print('Solution #%i' % self.__solution_count)
@@ -40,7 +40,7 @@ class NursesPartialSolutionPrinter(cp_model.CpSolverSolutionCallback):
                             print('  Nurse #%i is working shift #%i' % (n, s))
             print()
 
-    def SolutionCount(self):
+    def solution_count(self):
         return self.__solution_count
 
 
@@ -126,7 +126,7 @@ def main():
     print('  - conflicts       : %i' % solver.NumConflicts())
     print('  - branches        : %i' % solver.NumBranches())
     print('  - wall time       : %f ms' % solver.WallTime())
-    print('  - solutions found : %i' % solution_printer.SolutionCount())
+    print('  - solutions found : %i' % solution_printer.solution_count())
 
 
 if __name__ == '__main__':
diff --git a/examples/python/qubo_sat.py b/examples/python/qubo_sat.py
index f1070ad27b..11d3b1d475 100644
--- a/examples/python/qubo_sat.py
+++ b/examples/python/qubo_sat.py
@@ -650,7 +650,7 @@ class ObjectiveSolutionPrinter(cp_model.CpSolverSolutionCallback):
         self.__solution_count = 0
         self.__start_time = time.time()
 
-    def OnSolutionCallback(self):
+    def on_solution_callback(self):
         """Called at each new solution."""
         current_time = time.time()
         objective = self.ObjectiveValue()
@@ -659,7 +659,7 @@ class ObjectiveSolutionPrinter(cp_model.CpSolverSolutionCallback):
                objective, self.BestObjectiveBound()))
         self.__solution_count += 1
 
-    def SolutionCount(self):
+    def solution_count(self):
         return self.__solution_count
 
 def solve_qubo():
@@ -706,7 +706,7 @@ def solve_qubo():
     print('  - conflicts       : %i' % solver.NumConflicts())
     print('  - branches        : %i' % solver.NumBranches())
     print('  - wall time       : %f ms' % solver.WallTime())
-    print('  - solutions found : %i' % solution_printer.SolutionCount())
+    print('  - solutions found : %i' % solution_printer.solution_count())
 
 
 if __name__ == '__main__':
diff --git a/examples/python/rcpsp_sat.py b/examples/python/rcpsp_sat.py
index 15debd0c71..cc618b99c6 100644
--- a/examples/python/rcpsp_sat.py
+++ b/examples/python/rcpsp_sat.py
@@ -24,15 +24,15 @@ from google.protobuf import text_format
 from ortools.data import pywraprcpsp
 from ortools.sat.python import cp_model
 
-Parser = argparse.ArgumentParser()
-Parser.add_argument(
+PARSER = argparse.ArgumentParser()
+PARSER.add_argument(
     '--input', default="", help='Input file to parse and solve.')
-Parser.add_argument(
+PARSER.add_argument(
     '--output_proto',
     default="",
     help='Output file to write the cp_model'
     'proto to.')
-Parser.add_argument('--params', default="", help='Sat solver parameters.')
+PARSER.add_argument('--params', default="", help='Sat solver parameters.')
 
 
 class SolutionPrinter(cp_model.CpSolverSolutionCallback):
@@ -43,7 +43,7 @@ class SolutionPrinter(cp_model.CpSolverSolutionCallback):
         self.__solution_count = 0
         self.__start_time = time.time()
 
-    def OnSolutionCallback(self):
+    def on_solution_callback(self):
         current_time = time.time()
         objective = self.ObjectiveValue()
         print('Solution %i, time = %f s, objective = %i' %
@@ -52,7 +52,7 @@ class SolutionPrinter(cp_model.CpSolverSolutionCallback):
         self.__solution_count += 1
 
 
-def SolveRcpsp(problem, proto_file, params):
+def solve_rcpsp(problem, proto_file, params):
     """Parse and solve a given RCPSP problem in proto format."""
 
     # Determine problem type.
@@ -286,8 +286,8 @@ def SolveRcpsp(problem, proto_file, params):
 def main(args):
     rcpsp_parser = pywraprcpsp.RcpspParser()
     rcpsp_parser.ParseFile(args.input)
-    SolveRcpsp(rcpsp_parser.Problem(), args.output_proto, args.params)
+    solve_rcpsp(rcpsp_parser.Problem(), args.output_proto, args.params)
 
 
 if __name__ == '__main__':
-    main(Parser.parse_args())
+    main(PARSER.parse_args())
diff --git a/examples/python/shift_scheduling_sat.py b/examples/python/shift_scheduling_sat.py
index 64bd4d329a..0de1ada719 100644
--- a/examples/python/shift_scheduling_sat.py
+++ b/examples/python/shift_scheduling_sat.py
@@ -21,13 +21,13 @@ from google.protobuf import text_format
 
 from ortools.sat.python import cp_model
 
-Parser = argparse.ArgumentParser()
-Parser.add_argument(
+PARSER = argparse.ArgumentParser()
+PARSER.add_argument(
     '--output_proto',
     default="",
     help='Output file to write the cp_model'
     'proto to.')
-Parser.add_argument('--params', default="", help='Sat solver parameters.')
+PARSER.add_argument('--params', default="", help='Sat solver parameters.')
 
 
 class ObjectiveSolutionPrinter(cp_model.CpSolverSolutionCallback):
@@ -38,7 +38,7 @@ class ObjectiveSolutionPrinter(cp_model.CpSolverSolutionCallback):
         self.__solution_count = 0
         self.__start_time = time.time()
 
-    def OnSolutionCallback(self):
+    def on_solution_callback(self):
         """Called on each new solution."""
         current_time = time.time()
         objective = self.ObjectiveValue()
@@ -47,7 +47,7 @@ class ObjectiveSolutionPrinter(cp_model.CpSolverSolutionCallback):
                objective, self.BestObjectiveBound()))
         self.__solution_count += 1
 
-    def SolutionCount(self):
+    def solution_count(self):
         """Returns the number of solutions found."""
         return self.__solution_count
 
@@ -453,7 +453,7 @@ def solve_shift_scheduling(params, output_proto):
     print('  - conflicts       : %i' % solver.NumConflicts())
     print('  - branches        : %i' % solver.NumBranches())
     print('  - wall time       : %f ms' % solver.WallTime())
-    print('  - solutions found : %i' % solution_printer.SolutionCount())
+    print('  - solutions found : %i' % solution_printer.solution_count())
 
 
 def main(args):
@@ -462,4 +462,4 @@ def main(args):
 
 
 if __name__ == '__main__':
-    main(Parser.parse_args())
+    main(PARSER.parse_args())
diff --git a/examples/python/single_machine_scheduling_with_setup_release_due_dates_sat.py b/examples/python/single_machine_scheduling_with_setup_release_due_dates_sat.py
index 082f4ff344..dba2d55ebc 100644
--- a/examples/python/single_machine_scheduling_with_setup_release_due_dates_sat.py
+++ b/examples/python/single_machine_scheduling_with_setup_release_due_dates_sat.py
@@ -45,7 +45,7 @@ class SolutionPrinter(cp_model.CpSolverSolutionCallback):
         cp_model.CpSolverSolutionCallback.__init__(self)
         self.__solution_count = 0
 
-    def OnSolutionCallback(self):
+    def on_solution_callback(self):
         print('Solution %i, time = %f s, objective = %i' %
               (self.__solution_count, self.WallTime(), self.ObjectiveValue()))
         self.__solution_count += 1
diff --git a/examples/python/steel_mill_slab_sat.py b/examples/python/steel_mill_slab_sat.py
index 13c9dbd545..3d36cc1b17 100644
--- a/examples/python/steel_mill_slab_sat.py
+++ b/examples/python/steel_mill_slab_sat.py
@@ -36,7 +36,7 @@ PARSER.add_argument(
     help='Output file to write the cp_model proto to.')
 
 
-def BuildProblem(problem_id):
+def build_problem(problem_id):
     """Build problem data."""
     if problem_id == 0:
         capacities = [
@@ -270,7 +270,7 @@ class SteelMillSlabSolutionPrinter(cp_model.CpSolverSolutionCallback):
         self.__all_slabs = range(len(assign[0]))
         self.__start_time = time.time()
 
-    def OnSolutionCallback(self):
+    def on_solution_callback(self):
         current_time = time.time()
         objective = sum(self.Value(l) for l in self.__loss)
         print('Solution %i, time = %f s, objective = %i' %
@@ -299,7 +299,7 @@ class SolutionPrinterWithObjective(cp_model.CpSolverSolutionCallback):
         self.__solution_count = 0
         self.__start_time = time.time()
 
-    def OnSolutionCallback(self):
+    def on_solution_callback(self):
         current_time = time.time()
         print('Solution %i, time = %f s, objective = %i' %
               (self.__solution_count, current_time - self.__start_time,
@@ -307,10 +307,10 @@ class SolutionPrinterWithObjective(cp_model.CpSolverSolutionCallback):
         self.__solution_count += 1
 
 
-def SteelMillSlab(problem, break_symmetries, output_proto):
+def steel_mill_slab(problem, break_symmetries, output_proto):
     """Solves the Steel Mill Slab Problem."""
     ### Load problem.
-    (num_slabs, capacities, num_colors, orders) = BuildProblem(problem)
+    (num_slabs, capacities, num_colors, orders) = build_problem(problem)
 
     num_orders = len(orders)
     num_capacities = len(capacities)
@@ -458,15 +458,15 @@ class AllSolutionsCollector(cp_model.CpSolverSolutionCallback):
         self.__solutions = []
         self.__variables = variables
 
-    def OnSolutionCallback(self):
+    def on_solution_callback(self):
         solution = [self.Value(v) for v in self.__variables]
         self.__solutions.append(tuple(solution))
 
-    def AllSolutions(self):
+    def all_solutions(self):
         return self.__solutions
 
 
-def CollectValidSlabs(capacities, colors, widths, loss_array, all_colors):
+def collect_valid_slabs(capacities, colors, widths, loss_array, all_colors):
     """Collect valid columns (assign, loss) for one slab."""
     max_capacity = max(capacities)
     all_orders = range(len(colors))
@@ -505,13 +505,13 @@ def CollectValidSlabs(capacities, colors, widths, loss_array, all_colors):
     collector = AllSolutionsCollector(assign + [loss, load])
     solver.SearchForAllSolutions(model, collector)
     print('Collect Valid Slabs...DONE')
-    return collector.AllSolutions()
+    return collector.all_solutions()
 
 
-def SteelMillSlabWithValidSlabs(problem, break_symmetries, output_proto):
+def steel_mill_slab_with_valid_slabs(problem, break_symmetries, output_proto):
     """Solves the Steel Mill Slab Problem."""
     ### Load problem.
-    (num_slabs, capacities, num_colors, orders) = BuildProblem(problem)
+    (num_slabs, capacities, num_colors, orders) = build_problem(problem)
 
     num_orders = len(orders)
     num_capacities = len(capacities)
@@ -543,8 +543,8 @@ def SteelMillSlabWithValidSlabs(problem, break_symmetries, output_proto):
     ]
     losses = [model.NewIntVar(0, max_loss, 'loss_%i' % s) for s in all_slabs]
 
-    unsorted_valid_slabs = CollectValidSlabs(capacities, colors, widths,
-                                             loss_array, all_colors)
+    unsorted_valid_slabs = collect_valid_slabs(capacities, colors, widths,
+                                               loss_array, all_colors)
     # Sort slab by descending load/loss. Remove duplicates.
     valid_slabs = sorted(
         unsorted_valid_slabs, key=lambda c: 1000 * c[-1] + c[-2])
@@ -646,14 +646,13 @@ def SteelMillSlabWithValidSlabs(problem, break_symmetries, output_proto):
         print('No solution')
 
 
-def SteelMillSlabWithColumnGeneration(problem, output_proto):
+def steel_mill_slab_with_column_generation(problem, output_proto):
     """Solves the Steel Mill Slab Problem."""
     ### Load problem.
-    (num_slabs, capacities, num_colors, orders) = BuildProblem(problem)
+    (num_slabs, capacities, num_colors, orders) = build_problem(problem)
 
     num_orders = len(orders)
     num_capacities = len(capacities)
-    all_slabs = range(num_slabs)
     all_colors = range(num_colors)
     all_orders = range(len(orders))
     print('Solving steel mill with %i orders, %i slabs, and %i capacities' %
@@ -671,8 +670,8 @@ def SteelMillSlabWithColumnGeneration(problem, output_proto):
     ### Model problem.
 
     # Generate all valid slabs (columns)
-    unsorted_valid_slabs = CollectValidSlabs(capacities, colors, widths,
-                                             loss_array, all_colors)
+    unsorted_valid_slabs = collect_valid_slabs(capacities, colors, widths,
+                                               loss_array, all_colors)
     # Sort slab by descending load/loss. Remove duplicates.
     valid_slabs = sorted(
         unsorted_valid_slabs, key=lambda c: 1000 * c[-1] + c[-2])
@@ -722,14 +721,13 @@ def SteelMillSlabWithColumnGeneration(problem, output_proto):
         print('No solution')
 
 
-def SteelMillSlabWithMipColumnGeneration(problem):
+def steel_mill_slab_with_mip_column_generation(problem):
     """Solves the Steel Mill Slab Problem."""
     ### Load problem.
-    (num_slabs, capacities, num_colors, orders) = BuildProblem(problem)
+    (num_slabs, capacities, num_colors, orders) = build_problem(problem)
 
     num_orders = len(orders)
     num_capacities = len(capacities)
-    all_slabs = range(num_slabs)
     all_colors = range(num_colors)
     all_orders = range(len(orders))
     print('Solving steel mill with %i orders, %i slabs, and %i capacities' %
@@ -748,8 +746,8 @@ def SteelMillSlabWithMipColumnGeneration(problem):
 
     # Generate all valid slabs (columns)
     start = time.time()
-    unsorted_valid_slabs = CollectValidSlabs(capacities, colors, widths,
-                                             loss_array, all_colors)
+    unsorted_valid_slabs = collect_valid_slabs(capacities, colors, widths,
+                                               loss_array, all_colors)
     # Sort slab by descending load/loss. Remove duplicates.
     valid_slabs = sorted(
         unsorted_valid_slabs, key=lambda c: 1000 * c[-1] + c[-2])
@@ -792,14 +790,14 @@ def SteelMillSlabWithMipColumnGeneration(problem):
 def main(args):
     '''Main function'''
     if args.solver == 'sat':
-        SteelMillSlab(args.problem, args.break_symmetries, args.output_proto)
+        steel_mill_slab(args.problem, args.break_symmetries, args.output_proto)
     elif args.solver == 'sat_table':
-        SteelMillSlabWithValidSlabs(args.problem, args.break_symmetries,
-                                    args.output_proto)
+        steel_mill_slab_with_valid_slabs(args.problem, args.break_symmetries,
+                                         args.output_proto)
     elif args.solver == 'sat_column':
-        SteelMillSlabWithColumnGeneration(args.problem, args.output_proto)
+        steel_mill_slab_with_column_generation(args.problem, args.output_proto)
     else:  # 'mip_column'
-        SteelMillSlabWithMipColumnGeneration(args.problem)
+        steel_mill_slab_with_mip_column_generation(args.problem)
 
 
 if __name__ == '__main__':
diff --git a/examples/python/tasks_and_workers_assignment_sat.py b/examples/python/tasks_and_workers_assignment_sat.py
index e1d1d4f45f..74b985054e 100644
--- a/examples/python/tasks_and_workers_assignment_sat.py
+++ b/examples/python/tasks_and_workers_assignment_sat.py
@@ -24,7 +24,7 @@ class ObjectivePrinter(cp_model.CpSolverSolutionCallback):
         cp_model.CpSolverSolutionCallback.__init__(self)
         self.__solution_count = 0
 
-    def OnSolutionCallback(self):
+    def on_solution_callback(self):
         print('Solution %i, time = %f s, objective = %i' %
               (self.__solution_count, self.WallTime(), self.ObjectiveValue()))
         self.__solution_count += 1
diff --git a/examples/python/vendor_scheduling_sat.py b/examples/python/vendor_scheduling_sat.py
index fecf35dc59..166e61e4c7 100644
--- a/examples/python/vendor_scheduling_sat.py
+++ b/examples/python/vendor_scheduling_sat.py
@@ -33,7 +33,7 @@ class SolutionPrinter(cp_model.CpSolverSolutionCallback):
         self.__hours_stat = hours_stat
         self.__min_vendors = min_vendors
 
-    def OnSolutionCallback(self):
+    def on_solution_callback(self):
         """Called at each new solution."""
         self.__solution_count += 1
         print('Solution %i: ', self.__solution_count)
@@ -50,7 +50,7 @@ class SolutionPrinter(cp_model.CpSolverSolutionCallback):
             print()
         print()
 
-    def SolutionCount(self):
+    def solution_count(self):
         """Returns the number of solution found."""
         return self.__solution_count
 
@@ -137,8 +137,8 @@ def main():
     print('  - conflicts : %i' % solver.NumConflicts())
     print('  - branches  : %i' % solver.NumBranches())
     print('  - wall time : %f s' % solver.WallTime())
-    print(
-        '  - number of solutions found: %i' % solution_printer.SolutionCount())
+    print('  - number of solutions found: %i' % 
+          solution_printer.solution_count())
 
 
 if __name__ == '__main__':
diff --git a/examples/python/wedding_optimal_chart_sat.py b/examples/python/wedding_optimal_chart_sat.py
index 45f1704e18..1f2d4c2c2b 100644
--- a/examples/python/wedding_optimal_chart_sat.py
+++ b/examples/python/wedding_optimal_chart_sat.py
@@ -53,7 +53,7 @@ class WeddingChartPrinter(cp_model.CpSolverSolutionCallback):
         self.__num_tables = num_tables
         self.__num_guests = num_guests
 
-    def OnSolutionCallback(self):
+    def on_solution_callback(self):
         current_time = time.time()
         objective = self.ObjectiveValue()
         print("Solution %i, time = %f s, objective = %i" %
@@ -67,7 +67,7 @@ class WeddingChartPrinter(cp_model.CpSolverSolutionCallback):
                 if self.Value(self.__seats[(t, g)]):
                     print("  " + self.__names[g])
 
-    def NumSolutions(self):
+    def num_solutions(self):
         return self.__solution_count
 
 
@@ -116,7 +116,7 @@ def BuildData():
     return num_tables, table_capacity, min_known_neighbors, C, names
 
 
-def SolveWithDiscreteModel():
+def solve_with_discrete_model():
     num_tables, table_capacity, min_known_neighbors, C, names = BuildData()
 
     num_guests = len(C)
@@ -203,12 +203,7 @@ def SolveWithDiscreteModel():
     print("  - conflicts    : %i" % solver.NumConflicts())
     print("  - branches     : %i" % solver.NumBranches())
     print("  - wall time    : %f ms" % solver.WallTime())
-    print("  - num solutions: %i" % solution_printer.NumSolutions())
+    print("  - num solutions: %i" % solution_printer.num_solutions())
 
 
-def main():
-    SolveWithDiscreteModel()
-
-
-if __name__ == "__main__":
-    main()
+solve_with_discrete_model()
diff --git a/ortools/sat/python/cp_model.py b/ortools/sat/python/cp_model.py
index 46e5590c38..1bdbf797d3 100644
--- a/ortools/sat/python/cp_model.py
+++ b/ortools/sat/python/cp_model.py
@@ -1374,6 +1374,11 @@ class CpSolverSolutionCallback(pywrapsat.SolutionCallback):
     and Value() methods.
     """
 
+    def OnSolutionCallback(self):
+        """Proxy to the same method with different naming convention."""
+        self.on_solution_callback()
+
+
     def BooleanValue(self, lit):
         """Returns the boolean value of a boolean literal.
 
diff --git a/ortools/sat/samples/channeling_sample_sat.py b/ortools/sat/samples/channeling_sample_sat.py
index fa73f2aa7a..25a37fff52 100644
--- a/ortools/sat/samples/channeling_sample_sat.py
+++ b/ortools/sat/samples/channeling_sample_sat.py
@@ -27,13 +27,13 @@ class VarArraySolutionPrinter(cp_model.CpSolverSolutionCallback):
         self.__variables = variables
         self.__solution_count = 0
 
-    def OnSolutionCallback(self):
+    def on_solution_callback(self):
         self.__solution_count += 1
         for v in self.__variables:
             print('%s=%i' % (v, self.Value(v)), end=' ')
         print()
 
-    def SolutionCount(self):
+    def solution_count(self):
         return self.__solution_count
 
 
diff --git a/ortools/sat/samples/cp_is_fun_sat.py b/ortools/sat/samples/cp_is_fun_sat.py
index 9d12d9c111..10837e57c7 100644
--- a/ortools/sat/samples/cp_is_fun_sat.py
+++ b/ortools/sat/samples/cp_is_fun_sat.py
@@ -34,13 +34,13 @@ class VarArraySolutionPrinter(cp_model.CpSolverSolutionCallback):
         self.__variables = variables
         self.__solution_count = 0
 
-    def OnSolutionCallback(self):
+    def on_solution_callback(self):
         self.__solution_count += 1
         for v in self.__variables:
             print('%s=%i' % (v, self.Value(v)), end=' ')
         print()
 
-    def SolutionCount(self):
+    def solution_count(self):
         return self.__solution_count
         # [END solution_printing]
 
@@ -93,7 +93,7 @@ def CPIsFunSat():
     print('  - conflicts       : %i' % solver.NumConflicts())
     print('  - branches        : %i' % solver.NumBranches())
     print('  - wall time       : %f ms' % solver.WallTime())
-    print('  - solutions found : %i' % solution_printer.SolutionCount())
+    print('  - solutions found : %i' % solution_printer.solution_count())
 
 
 if __name__ == '__main__':
diff --git a/ortools/sat/samples/search_for_all_solutions_sample_sat.py b/ortools/sat/samples/search_for_all_solutions_sample_sat.py
index ef1eebf8b7..29be9f3092 100644
--- a/ortools/sat/samples/search_for_all_solutions_sample_sat.py
+++ b/ortools/sat/samples/search_for_all_solutions_sample_sat.py
@@ -29,13 +29,13 @@ class VarArraySolutionPrinter(cp_model.CpSolverSolutionCallback):
         self.__variables = variables
         self.__solution_count = 0
 
-    def OnSolutionCallback(self):
+    def on_solution_callback(self):
         self.__solution_count += 1
         for v in self.__variables:
             print('%s=%i' % (v, self.Value(v)), end=' ')
         print()
 
-    def SolutionCount(self):
+    def solution_count(self):
         return self.__solution_count
         # [END print_solution]
 
@@ -68,7 +68,7 @@ def SearchForAllSolutionsSampleSat():
     # [END solve]
 
     print('Status = %s' % solver.StatusName(status))
-    print('Number of solutions found: %i' % solution_printer.SolutionCount())
+    print('Number of solutions found: %i' % solution_printer.solution_count())
 
 
 SearchForAllSolutionsSampleSat()
diff --git a/ortools/sat/samples/solve_and_print_intermediate_solutions_sample_sat.py b/ortools/sat/samples/solve_and_print_intermediate_solutions_sample_sat.py
index 2b133bd5c5..28f9b03555 100644
--- a/ortools/sat/samples/solve_and_print_intermediate_solutions_sample_sat.py
+++ b/ortools/sat/samples/solve_and_print_intermediate_solutions_sample_sat.py
@@ -30,7 +30,7 @@ class VarArrayAndObjectiveSolutionPrinter(cp_model.CpSolverSolutionCallback):
         self.__variables = variables
         self.__solution_count = 0
 
-    def OnSolutionCallback(self):
+    def on_solution_callback(self):
         print('Solution %i' % self.__solution_count)
         print('  objective value = %i' % self.ObjectiveValue())
         for v in self.__variables:
@@ -38,7 +38,7 @@ class VarArrayAndObjectiveSolutionPrinter(cp_model.CpSolverSolutionCallback):
         print()
         self.__solution_count += 1
 
-    def SolutionCount(self):
+    def solution_count(self):
         return self.__solution_count
         # [END print_solution]
 
@@ -75,7 +75,7 @@ def SolveAndPrintIntermediateSolutionsSampleSat():
     # [END solve]
 
     print('Status = %s' % solver.StatusName(status))
-    print('Number of solutions found: %i' % solution_printer.SolutionCount())
+    print('Number of solutions found: %i' % solution_printer.solution_count())
 
 
 SolveAndPrintIntermediateSolutionsSampleSat()
diff --git a/ortools/sat/samples/stop_after_n_solutions_sample_sat.py b/ortools/sat/samples/stop_after_n_solutions_sample_sat.py
index ec12a3831c..30925c04ce 100644
--- a/ortools/sat/samples/stop_after_n_solutions_sample_sat.py
+++ b/ortools/sat/samples/stop_after_n_solutions_sample_sat.py
@@ -28,7 +28,7 @@ class VarArraySolutionPrinterWithLimit(cp_model.CpSolverSolutionCallback):
         self.__solution_count = 0
         self.__solution_limit = limit
 
-    def OnSolutionCallback(self):
+    def on_solution_callback(self):
         self.__solution_count += 1
         for v in self.__variables:
             print('%s=%i' % (v, self.Value(v)), end=' ')
@@ -37,7 +37,7 @@ class VarArraySolutionPrinterWithLimit(cp_model.CpSolverSolutionCallback):
             print('Stop search after %i solutions' % self.__solution_limit)
             self.StopSearch()
 
-    def SolutionCount(self):
+    def solution_count(self):
         return self.__solution_count
 
 
@@ -56,8 +56,8 @@ def StopAfterNSolutionsSampleSat():
     solution_printer = VarArraySolutionPrinterWithLimit([x, y, z], 5)
     status = solver.SearchForAllSolutions(model, solution_printer)
     print('Status = %s' % solver.StatusName(status))
-    print('Number of solutions found: %i' % solution_printer.SolutionCount())
-    assert solution_printer.SolutionCount() == 5
+    print('Number of solutions found: %i' % solution_printer.solution_count())
+    assert solution_printer.solution_count() == 5
 
 
 StopAfterNSolutionsSampleSat()