py3: OpenSCAD: use io.open more explicit

src/Mod/OpenSCAD/OpenSCADUtils.py

@@ -41,10 +41,7 @@ except AttributeError:
         from PySide import QtGui
         return QtGui.QApplication.translate(context, text, None)
 
-try:
-    from io import open
-except ImportError:
-    from codecs import open
+import io
 
 try:
     import FreeCAD
@@ -180,7 +177,7 @@ def callopenscadstring(scadstr,outputext='csg'):
     import os,tempfile,time
     dir1=tempfile.gettempdir()
     inputfilename=os.path.join(dir1,'%s.scad' % next(tempfilenamegen))
-    inputfile = open(inputfilename,'w', encoding="utf8")
+    inputfile = io.open(inputfilename,'w', encoding="utf8")
     inputfile.write(scadstr)
     inputfile.close()
     outputfilename = callopenscad(inputfilename,outputext=outputext,\

src/Mod/OpenSCAD/exportCSG.py

@@ -50,7 +50,9 @@ convexity = 'convexity = %d' % conv
 #***************************************************************************
 # Radius values not fixed for value apart from cylinder & Cone
 # no doubt there will be a problem when they do implement Value
-pythonopen = open
+if open.__module__ in ['__builtin__', 'io']:
+    pythonopen = open # to distinguish python built-in open function from the one declared here
+
 
 def center(b):
     if b == 2:
@@ -247,7 +249,7 @@ def export(exportList,filename):
     # process Objects
     print("\nStart Export 0.1d\n")
     print("Open Output File")
-    csg = pythonopen(filename,'w', encoding="utf8")
+    csg = pythonopen(filename,'w')
     print("Write Initial Output")
     # Not sure if comments as per scad are allowed in csg file              
     csg.write("// CSG file generated from FreeCAD %s\n" % \

src/Mod/OpenSCAD/importCSG.py

@@ -33,7 +33,7 @@ __url__ = ["http://www.sloan-home.co.uk/ImportCSG"]
 
 printverbose = False
 
-import FreeCAD, os, sys
+import FreeCAD, io, os, sys
 if FreeCAD.GuiUp:
     import FreeCADGui
     gui = True
@@ -52,8 +52,6 @@ from OpenSCADUtils import *
 params = FreeCAD.ParamGet("User parameter:BaseApp/Preferences/Mod/OpenSCAD")
 printverbose = params.GetBool('printVerbose',False)
 
-pythonopen = open
-
 # Get the token map from the lexer.  This is required.
 import tokrules
 from tokrules import tokens
@@ -135,7 +133,7 @@ def processcsg(filename):
     if printverbose: print('Parser Loaded')
     # Give the lexer some input
     #f=open('test.scad', 'r')
-    f = pythonopen(filename, 'r', encoding="utf8")
+    f = io.open(filename, 'r', encoding="utf8")
     #lexer.input(f.read())
 
     if printverbose: print('Start Parser')