Set locale in write/print functions (#830)

* Add setlocale to write/print functions

* Add test

* Update CHANGELOG

* Add sanity check:

* Try portugese locale

* Try loading de_DE locale in CI

* Update locale in runner

* Add comment

---------

Co-authored-by: Mohammed Ghannam <mohammad.m.ghannam@gmail.com>
Co-authored-by: Mohammed Ghannam <ghannam@zib.de>

Author: Joao-Dionisio

.github/workflows/coverage.yml

@@ -43,6 +43,7 @@ jobs:
 
       - name: Run pyscipopt tests
         run: |
+          sudo apt-get install tzdata locales -y && sudo locale-gen pt_PT && sudo update-locale # add pt_PT locale that is used in tests
           coverage run -m pytest
           coverage report -m
           coverage xml

CHANGELOG.md

@@ -6,6 +6,7 @@
 - Add SCIP function SCIPgetTreesizeEstimation and wrapper getTreesizeEstimation
 - Add recipes sub-package
 ### Fixed
+- Fixed incorrect writing/printing when user had a non-default locale
 ### Changed
 ### Removed
 

src/pyscipopt/scip.pxi

@@ -6,6 +6,7 @@ from os.path import splitext
 import os
 import sys
 import warnings
+import locale
 
 cimport cython
 from cpython cimport Py_INCREF, Py_DECREF
@@ -1128,8 +1129,13 @@ cdef class Model:
 
     def printVersion(self):
         """Print version, copyright information and compile mode"""
+        user_locale = locale.getlocale()
+        locale.setlocale(locale.LC_ALL, "C")
+
         SCIPprintVersion(self._scip, NULL)
 
+        locale.setlocale(locale.LC_ALL, user_locale)
+
     def getProbName(self):
         """Retrieve problem name"""
         return bytes(SCIPgetProbName(self._scip)).decode('UTF-8')
@@ -1455,6 +1461,9 @@ cdef class Model:
         :param genericnames: indicates whether the problem should be written with generic variable and constraint names (Default value = False)
 
         """
+        user_locale = locale.getlocale()
+        locale.setlocale(locale.LC_ALL, "C")
+
         str_absfile = abspath(filename)
         absfile = str_conversion(str_absfile)
         fn, ext = splitext(absfile)
@@ -1468,6 +1477,8 @@ cdef class Model:
             PY_SCIP_CALL(SCIPwriteOrigProblem(self._scip, fn, ext, genericnames))
         print('wrote problem to file ' + str_absfile)
 
+        locale.setlocale(locale.LC_ALL, user_locale)
+
     # Variable Functions
 
     def addVar(self, name='', vtype='C', lb=0.0, ub=None, obj=0.0, pricedVar=False, pricedVarScore=1.0):
@@ -4373,9 +4384,14 @@ cdef class Model:
         """writes current LP to a file
         :param filename: file name (Default value = "LP.lp")
         """
+        user_locale = locale.getlocale()
+        locale.setlocale(locale.LC_ALL, "C")
+
         absfile = str_conversion(abspath(filename))
         PY_SCIP_CALL( SCIPwriteLP(self._scip, absfile) )
 
+        locale.setlocale(locale.LC_ALL, user_locale)
+
     def createSol(self, Heur heur = None):
         """Create a new primal solution.
 
@@ -4413,19 +4429,30 @@ cdef class Model:
 
     def printBestSol(self, write_zeros=False):
         """Prints the best feasible primal solution."""
+        user_locale = locale.getlocale()
+        locale.setlocale(locale.LC_ALL, "C")
+
         PY_SCIP_CALL(SCIPprintBestSol(self._scip, NULL, write_zeros))
 
+        locale.setlocale(locale.LC_ALL, user_locale)
+
     def printSol(self, Solution solution=None, write_zeros=False):
-      """Print the given primal solution.
+        """Print the given primal solution.
+
+        Keyword arguments:
+        solution -- solution to print
+        write_zeros -- include variables that are set to zero
+        """
+
+        user_locale = locale.getlocale()
+        locale.setlocale(locale.LC_ALL, "C")
 
-      Keyword arguments:
-      solution -- solution to print
-      write_zeros -- include variables that are set to zero
-      """
-      if solution is None:
-         PY_SCIP_CALL(SCIPprintSol(self._scip, NULL, NULL, write_zeros))
-      else:
-         PY_SCIP_CALL(SCIPprintSol(self._scip, solution.sol, NULL, write_zeros))
+        if solution is None:
+            PY_SCIP_CALL(SCIPprintSol(self._scip, NULL, NULL, write_zeros))
+        else:
+            PY_SCIP_CALL(SCIPprintSol(self._scip, solution.sol, NULL, write_zeros))
+        
+        locale.setlocale(locale.LC_ALL, user_locale)
 
     def writeBestSol(self, filename="origprob.sol", write_zeros=False):
         """Write the best feasible primal solution to a file.
@@ -4434,24 +4461,35 @@ cdef class Model:
         filename -- name of the output file
         write_zeros -- include variables that are set to zero
         """
+
+        user_locale = locale.getlocale()
+        locale.setlocale(locale.LC_ALL, "C")
+
         # use this doubled opening pattern to ensure that IOErrors are
         #   triggered early and in Python not in C,Cython or SCIP.
         with open(filename, "w") as f:
             cfile = fdopen(f.fileno(), "w")
             PY_SCIP_CALL(SCIPprintBestSol(self._scip, cfile, write_zeros))
 
+        locale.setlocale(locale.LC_ALL, user_locale)
+
     def writeBestTransSol(self, filename="transprob.sol", write_zeros=False):
         """Write the best feasible primal solution for the transformed problem to a file.
 
         Keyword arguments:
         filename -- name of the output file
         write_zeros -- include variables that are set to zero
         """
+        user_locale = locale.getlocale()
+        locale.setlocale(locale.LC_ALL, "C")
+
         # use this double opening pattern to ensure that IOErrors are
         #   triggered early and in python not in C, Cython or SCIP.
         with open(filename, "w") as f:
             cfile = fdopen(f.fileno(), "w")
             PY_SCIP_CALL(SCIPprintBestTransSol(self._scip, cfile, write_zeros))
+        
+        locale.setlocale(locale.LC_ALL, user_locale)
 
     def writeSol(self, Solution solution, filename="origprob.sol", write_zeros=False):
         """Write the given primal solution to a file.
@@ -4461,11 +4499,16 @@ cdef class Model:
         filename -- name of the output file
         write_zeros -- include variables that are set to zero
         """
+        user_locale = locale.getlocale()
+        locale.setlocale(locale.LC_ALL, "C")
+
         # use this doubled opening pattern to ensure that IOErrors are
         #   triggered early and in Python not in C,Cython or SCIP.
         with open(filename, "w") as f:
             cfile = fdopen(f.fileno(), "w")
             PY_SCIP_CALL(SCIPprintSol(self._scip, solution.sol, cfile, write_zeros))
+        
+        locale.setlocale(locale.LC_ALL, user_locale)
 
     def writeTransSol(self, Solution solution, filename="transprob.sol", write_zeros=False):
         """Write the given transformed primal solution to a file.
@@ -4475,11 +4518,16 @@ cdef class Model:
         filename -- name of the output file
         write_zeros -- include variables that are set to zero
         """
+        user_locale = locale.getlocale()
+        locale.setlocale(locale.LC_ALL, "C")
+
         # use this doubled opening pattern to ensure that IOErrors are
         #   triggered early and in Python not in C,Cython or SCIP.
         with open(filename, "w") as f:
             cfile = fdopen(f.fileno(), "w")
             PY_SCIP_CALL(SCIPprintTransSol(self._scip, solution.sol, cfile, write_zeros))
+        
+        locale.setlocale(locale.LC_ALL, user_locale)
 
     # perhaps this should not be included as it implements duplicated functionality
     #   (as does it's namesake in SCIP)
@@ -4737,8 +4785,13 @@ cdef class Model:
         :param Variable var: variable
 
         """
+        user_locale = locale.getlocale()
+        locale.setlocale(locale.LC_ALL, "C")
+
         PY_SCIP_CALL(SCIPwriteVarName(self._scip, NULL, var.scip_var, False))
 
+        locale.setlocale(locale.LC_ALL, user_locale)
+
     def getStage(self):
         """Retrieve current SCIP stage"""
         return SCIPgetStage(self._scip)
@@ -4864,19 +4917,29 @@ cdef class Model:
 
     def printStatistics(self):
         """Print statistics."""
+        user_locale = locale.getlocale()
+        locale.setlocale(locale.LC_ALL, "C")
+
         PY_SCIP_CALL(SCIPprintStatistics(self._scip, NULL))
 
+        locale.setlocale(locale.LC_ALL, user_locale)
+
     def writeStatistics(self, filename="origprob.stats"):
-      """Write statistics to a file.
+        """Write statistics to a file.
 
-      Keyword arguments:
-      filename -- name of the output file
-      """
-      # use this doubled opening pattern to ensure that IOErrors are
-      #   triggered early and in Python not in C,Cython or SCIP.
-      with open(filename, "w") as f:
-          cfile = fdopen(f.fileno(), "w")
-          PY_SCIP_CALL(SCIPprintStatistics(self._scip, cfile))
+        Keyword arguments:
+        filename -- name of the output file
+        """
+        user_locale = locale.getlocale()
+        locale.setlocale(locale.LC_ALL, "C")
+
+        # use this doubled opening pattern to ensure that IOErrors are
+        #   triggered early and in Python not in C,Cython or SCIP.
+        with open(filename, "w") as f:
+            cfile = fdopen(f.fileno(), "w")
+            PY_SCIP_CALL(SCIPprintStatistics(self._scip, cfile))
+        
+        locale.setlocale(locale.LC_ALL, user_locale)
 
     def getNLPs(self):
         """gets total number of LPs solved so far"""
@@ -5070,11 +5133,16 @@ cdef class Model:
         :param onlychanged: write only modified parameters (Default value = True)
 
         """
+        user_locale = locale.getlocale()
+        locale.setlocale(locale.LC_ALL, "C")
+
         str_absfile = abspath(filename)
         absfile = str_conversion(str_absfile)
         PY_SCIP_CALL(SCIPwriteParams(self._scip, absfile, comments, onlychanged))
         print('wrote parameter settings to file ' + str_absfile)
 
+        locale.setlocale(locale.LC_ALL, user_locale)
+
     def resetParam(self, name):
         """Reset parameter setting to its default value
 

tests/test_model.py

@@ -300,3 +300,19 @@ def test_getTreesizeEstimation():
     m.optimize()
 
     assert m.getTreesizeEstimation() > 0
+   
+def test_locale():
+    import locale
+
+    m = Model()
+    x = m.addVar(lb=1.1)
+
+    locale.setlocale(locale.LC_NUMERIC, "pt_PT")
+
+    assert locale.str(1.1) == "1,1"
+
+    m.writeProblem("model.cip")
+
+    with open("model.cip") as file:
+        assert "1,1" not in file.read()
+