diff --git a/devtools/batchbuild.py b/devtools/batchbuild.py
index 6f57945..0eb0690 100644
--- a/devtools/batchbuild.py
+++ b/devtools/batchbuild.py
@@ -18,62 +18,62 @@
         self.build_type = build_type
         self.generator = generator
 
-    def merged_with( self, build_desc ):
+    def merged_with(self, build_desc):
         """Returns a new BuildDesc by merging field content.
            Prefer build_desc fields to self fields for single valued field.
         """
-        return BuildDesc( self.prepend_envs + build_desc.prepend_envs,
+        return BuildDesc(self.prepend_envs + build_desc.prepend_envs,
                           self.variables + build_desc.variables,
                           build_desc.build_type or self.build_type,
-                          build_desc.generator or self.generator )
+                          build_desc.generator or self.generator)
 
-    def env( self ):
+    def env(self):
         environ = os.environ.copy()
         for values_by_name in self.prepend_envs:
             for var, value in list(values_by_name.items()):
                 var = var.upper()
                 if type(value) is unicode:
-                    value = value.encode( sys.getdefaultencoding() )
+                    value = value.encode(sys.getdefaultencoding())
                 if var in environ:
                     environ[var] = value + os.pathsep + environ[var]
                 else:
                     environ[var] = value
         return environ
 
-    def cmake_args( self ):
+    def cmake_args(self):
         args = ["-D%s" % var for var in self.variables]
         # skip build type for Visual Studio solution as it cause warning
         if self.build_type and 'Visual' not in self.generator:
-            args.append( "-DCMAKE_BUILD_TYPE=%s" % self.build_type )
+            args.append("-DCMAKE_BUILD_TYPE=%s" % self.build_type)
         if self.generator:
-            args.extend( ['-G', self.generator] )
+            args.extend(['-G', self.generator])
         return args
 
-    def __repr__( self ):
-        return "BuildDesc( %s, build_type=%s )" %  (" ".join( self.cmake_args()), self.build_type)
+    def __repr__(self):
+        return "BuildDesc(%s, build_type=%s)" %  (" ".join(self.cmake_args()), self.build_type)
 
 class BuildData:
-    def __init__( self, desc, work_dir, source_dir ):
+    def __init__(self, desc, work_dir, source_dir):
         self.desc = desc
         self.work_dir = work_dir
         self.source_dir = source_dir
-        self.cmake_log_path = os.path.join( work_dir, 'batchbuild_cmake.log' )
-        self.build_log_path = os.path.join( work_dir, 'batchbuild_build.log' )
+        self.cmake_log_path = os.path.join(work_dir, 'batchbuild_cmake.log')
+        self.build_log_path = os.path.join(work_dir, 'batchbuild_build.log')
         self.cmake_succeeded = False
         self.build_succeeded = False
 
     def execute_build(self):
         print('Build %s' % self.desc)
-        self._make_new_work_dir( )
-        self.cmake_succeeded = self._generate_makefiles( )
+        self._make_new_work_dir()
+        self.cmake_succeeded = self._generate_makefiles()
         if self.cmake_succeeded:
-            self.build_succeeded = self._build_using_makefiles( )
+            self.build_succeeded = self._build_using_makefiles()
         return self.build_succeeded
 
     def _generate_makefiles(self):
         print('  Generating makefiles: ', end=' ')
-        cmd = ['cmake'] + self.desc.cmake_args( ) + [os.path.abspath( self.source_dir )]
-        succeeded = self._execute_build_subprocess( cmd, self.desc.env(), self.cmake_log_path )
+        cmd = ['cmake'] + self.desc.cmake_args() + [os.path.abspath(self.source_dir)]
+        succeeded = self._execute_build_subprocess(cmd, self.desc.env(), self.cmake_log_path)
         print('done' if succeeded else 'FAILED')
         return succeeded
 
@@ -82,58 +82,58 @@
         cmd = ['cmake', '--build', self.work_dir]
         if self.desc.build_type:
             cmd += ['--config', self.desc.build_type]
-        succeeded = self._execute_build_subprocess( cmd, self.desc.env(), self.build_log_path )
+        succeeded = self._execute_build_subprocess(cmd, self.desc.env(), self.build_log_path)
         print('done' if succeeded else 'FAILED')
         return succeeded
 
     def _execute_build_subprocess(self, cmd, env, log_path):
-        process = subprocess.Popen( cmd, stdout=subprocess.PIPE, stderr=subprocess.STDOUT, cwd=self.work_dir,
-                                    env=env )
-        stdout, _ = process.communicate( )
+        process = subprocess.Popen(cmd, stdout=subprocess.PIPE, stderr=subprocess.STDOUT, cwd=self.work_dir,
+                                    env=env)
+        stdout, _ = process.communicate()
         succeeded = (process.returncode == 0)
-        with open( log_path, 'wb' ) as flog:
-            log = ' '.join( cmd ) + '\n' + stdout + '\nExit code: %r\n' % process.returncode
-            flog.write( fix_eol( log ) )
+        with open(log_path, 'wb') as flog:
+            log = ' '.join(cmd) + '\n' + stdout + '\nExit code: %r\n' % process.returncode
+            flog.write(fix_eol(log))
         return succeeded
 
     def _make_new_work_dir(self):
-        if os.path.isdir( self.work_dir ):
+        if os.path.isdir(self.work_dir):
             print('  Removing work directory', self.work_dir)
-            shutil.rmtree( self.work_dir, ignore_errors=True )
-        if not os.path.isdir( self.work_dir ):
-            os.makedirs( self.work_dir )
+            shutil.rmtree(self.work_dir, ignore_errors=True)
+        if not os.path.isdir(self.work_dir):
+            os.makedirs(self.work_dir)
 
-def fix_eol( stdout ):
+def fix_eol(stdout):
     """Fixes wrong EOL produced by cmake --build on Windows (\r\r\n instead of \r\n).
     """
-    return re.sub( '\r*\n', os.linesep, stdout )
+    return re.sub('\r*\n', os.linesep, stdout)
 
-def load_build_variants_from_config( config_path ):
-    with open( config_path, 'rb' ) as fconfig:
-        data = json.load( fconfig )
+def load_build_variants_from_config(config_path):
+    with open(config_path, 'rb') as fconfig:
+        data = json.load(fconfig)
     variants = data[ 'cmake_variants' ]
-    build_descs_by_axis = collections.defaultdict( list )
+    build_descs_by_axis = collections.defaultdict(list)
     for axis in variants:
         axis_name = axis["name"]
         build_descs = []
         if "generators" in axis:
             for generator_data in axis["generators"]:
                 for generator in generator_data["generator"]:
-                    build_desc = BuildDesc( generator=generator,
-                                            prepend_envs=generator_data.get("env_prepend") )
-                    build_descs.append( build_desc )
+                    build_desc = BuildDesc(generator=generator,
+                                            prepend_envs=generator_data.get("env_prepend"))
+                    build_descs.append(build_desc)
         elif "variables" in axis:
             for variables in axis["variables"]:
-                build_desc = BuildDesc( variables=variables )
-                build_descs.append( build_desc )
+                build_desc = BuildDesc(variables=variables)
+                build_descs.append(build_desc)
         elif "build_types" in axis:
             for build_type in axis["build_types"]:
-                build_desc = BuildDesc( build_type=build_type )
-                build_descs.append( build_desc )
-        build_descs_by_axis[axis_name].extend( build_descs )
+                build_desc = BuildDesc(build_type=build_type)
+                build_descs.append(build_desc)
+        build_descs_by_axis[axis_name].extend(build_descs)
     return build_descs_by_axis
 
-def generate_build_variants( build_descs_by_axis ):
+def generate_build_variants(build_descs_by_axis):
     """Returns a list of BuildDesc generated for the partial BuildDesc for each axis."""
     axis_names = list(build_descs_by_axis.keys())
     build_descs = []
@@ -141,8 +141,8 @@
         if len(build_descs):
             # for each existing build_desc and each axis build desc, create a new build_desc
             new_build_descs = []
-            for prototype_build_desc, axis_build_desc in itertools.product( build_descs, axis_build_descs):
-                new_build_descs.append( prototype_build_desc.merged_with( axis_build_desc ) )
+            for prototype_build_desc, axis_build_desc in itertools.product(build_descs, axis_build_descs):
+                new_build_descs.append(prototype_build_desc.merged_with(axis_build_desc))
             build_descs = new_build_descs
         else:
             build_descs = axis_build_descs
@@ -174,60 +174,57 @@
 </table>
 </body></html>''')
 
-def generate_html_report( html_report_path, builds ):
-    report_dir = os.path.dirname( html_report_path )
+def generate_html_report(html_report_path, builds):
+    report_dir = os.path.dirname(html_report_path)
     # Vertical axis: generator
     # Horizontal: variables, then build_type
-    builds_by_generator = collections.defaultdict( list )
+    builds_by_generator = collections.defaultdict(list)
     variables = set()
-    build_types_by_variable = collections.defaultdict( set )
+    build_types_by_variable = collections.defaultdict(set)
     build_by_pos_key = {} # { (generator, var_key, build_type): build }
     for build in builds:
-        builds_by_generator[build.desc.generator].append( build )
+        builds_by_generator[build.desc.generator].append(build)
         var_key = tuple(sorted(build.desc.variables))
-        variables.add( var_key )
-        build_types_by_variable[var_key].add( build.desc.build_type )
+        variables.add(var_key)
+        build_types_by_variable[var_key].add(build.desc.build_type)
         pos_key = (build.desc.generator, var_key, build.desc.build_type)
         build_by_pos_key[pos_key] = build
-    variables = sorted( variables )
+    variables = sorted(variables)
     th_vars = []
     th_build_types = []
     for variable in variables:
-        build_types = sorted( build_types_by_variable[variable] )
+        build_types = sorted(build_types_by_variable[variable])
         nb_build_type = len(build_types_by_variable[variable])
-        th_vars.append( '<th colspan="%d">%s</th>' % (nb_build_type, cgi.escape( ' '.join( variable ) ) ) )
+        th_vars.append('<th colspan="%d">%s</th>' % (nb_build_type, cgi.escape(' '.join(variable))))
         for build_type in build_types:
-            th_build_types.append( '<th>%s</th>' % cgi.escape(build_type) )
+            th_build_types.append('<th>%s</th>' % cgi.escape(build_type))
     tr_builds = []
-    for generator in sorted( builds_by_generator ):
-        tds = [ '<td>%s</td>\n' % cgi.escape( generator ) ]
+    for generator in sorted(builds_by_generator):
+        tds = [ '<td>%s</td>\n' % cgi.escape(generator) ]
         for variable in variables:
-            build_types = sorted( build_types_by_variable[variable] )
+            build_types = sorted(build_types_by_variable[variable])
             for build_type in build_types:
                 pos_key = (generator, variable, build_type)
                 build = build_by_pos_key.get(pos_key)
                 if build:
                     cmake_status = 'ok' if build.cmake_succeeded else 'FAILED'
                     build_status = 'ok' if build.build_succeeded else 'FAILED'
-                    cmake_log_url = os.path.relpath( build.cmake_log_path, report_dir )
-                    build_log_url = os.path.relpath( build.build_log_path, report_dir )
-                    td = '<td class="%s"><a href="%s" class="%s">CMake: %s</a>' % (
-                        build_status.lower(), cmake_log_url, cmake_status.lower(), cmake_status)
+                    cmake_log_url = os.path.relpath(build.cmake_log_path, report_dir)
+                    build_log_url = os.path.relpath(build.build_log_path, report_dir)
+                    td = '<td class="%s"><a href="%s" class="%s">CMake: %s</a>' % (                        build_status.lower(), cmake_log_url, cmake_status.lower(), cmake_status)
                     if build.cmake_succeeded:
-                        td += '<br><a href="%s" class="%s">Build: %s</a>' % (
-                            build_log_url, build_status.lower(), build_status)
+                        td += '<br><a href="%s" class="%s">Build: %s</a>' % (                            build_log_url, build_status.lower(), build_status)
                     td += '</td>'
                 else:
                     td = '<td></td>'
-                tds.append( td )
-        tr_builds.append( '<tr>%s</tr>' % '\n'.join( tds ) )
-    html = HTML_TEMPLATE.substitute(
-        title='Batch build report',
+                tds.append(td)
+        tr_builds.append('<tr>%s</tr>' % '\n'.join(tds))
+    html = HTML_TEMPLATE.substitute(        title='Batch build report',
         th_vars=' '.join(th_vars),
-        th_build_types=' '.join( th_build_types),
-        tr_builds='\n'.join( tr_builds ) )
-    with open( html_report_path, 'wt' ) as fhtml:
-        fhtml.write( html )
+        th_build_types=' '.join(th_build_types),
+        tr_builds='\n'.join(tr_builds))
+    with open(html_report_path, 'wt') as fhtml:
+        fhtml.write(html)
     print('HTML report generated in:', html_report_path)
 
 def main():
@@ -246,33 +243,33 @@
     parser.enable_interspersed_args()
     options, args = parser.parse_args()
     if len(args) < 3:
-        parser.error( "Missing one of WORK_DIR SOURCE_DIR CONFIG_JSON_PATH." )
+        parser.error("Missing one of WORK_DIR SOURCE_DIR CONFIG_JSON_PATH.")
     work_dir = args[0]
     source_dir = args[1].rstrip('/\\')
     config_paths = args[2:]
     for config_path in config_paths:
-        if not os.path.isfile( config_path ):
-            parser.error( "Can not read: %r" % config_path )
+        if not os.path.isfile(config_path):
+            parser.error("Can not read: %r" % config_path)
 
     # generate build variants
     build_descs = []
     for config_path in config_paths:
-        build_descs_by_axis = load_build_variants_from_config( config_path )
-        build_descs.extend( generate_build_variants( build_descs_by_axis ) )
+        build_descs_by_axis = load_build_variants_from_config(config_path)
+        build_descs.extend(generate_build_variants(build_descs_by_axis))
     print('Build variants (%d):' % len(build_descs))
     # assign build directory for each variant
-    if not os.path.isdir( work_dir ):
-        os.makedirs( work_dir )
+    if not os.path.isdir(work_dir):
+        os.makedirs(work_dir)
     builds = []
-    with open( os.path.join( work_dir, 'matrix-dir-map.txt' ), 'wt' ) as fmatrixmap:
-        for index, build_desc in enumerate( build_descs ):
-            build_desc_work_dir = os.path.join( work_dir, '%03d' % (index+1) )
-            builds.append( BuildData( build_desc, build_desc_work_dir, source_dir ) )
-            fmatrixmap.write( '%s: %s\n' % (build_desc_work_dir, build_desc) )
+    with open(os.path.join(work_dir, 'matrix-dir-map.txt'), 'wt') as fmatrixmap:
+        for index, build_desc in enumerate(build_descs):
+            build_desc_work_dir = os.path.join(work_dir, '%03d' % (index+1))
+            builds.append(BuildData(build_desc, build_desc_work_dir, source_dir))
+            fmatrixmap.write('%s: %s\n' % (build_desc_work_dir, build_desc))
     for build in builds:
         build.execute_build()
-    html_report_path = os.path.join( work_dir, 'batchbuild-report.html' )
-    generate_html_report( html_report_path, builds )
+    html_report_path = os.path.join(work_dir, 'batchbuild-report.html')
+    generate_html_report(html_report_path, builds)
     print('Done')