Pyqt4 to Pyqt5 and python code error - python-2.7

Question

i switch from Pyqt4 to Pyqt5 and from python2.7 to 3.4 and i found a bug in Pyqt5 so i upgrade it to the last version which is not suppoted by python3.4 . than i used python3.5 and it work fine except one module called pymaxwell.
always the app crash and closed and to confirm i go back to python2.7 and i use pyqt5 for python2.7 and the same error ; the app closed immediately and show me an error in a part in the code which is work well with pyqt4.
in the gif a comparaison between Pyqt4/Pyqt5 with python2.7
comparison
the part of the code which have problem:
self.btnMXSmxm()
self.mxs_filt.setChecked(True)
self.show_folder.setChecked(False)
inPath = self.input_mxs_scene_2.text();
self.input_mxs_scene.setText(inPath);
self.mxm_list.clear()
if len(inPath) == 0:
self.chosen_material.clear()
# loop over all mxs
else:
mxsList = self.input_mxs_scene.text()
print mxsList
if not len(mxsList) == 0:
scene = Cmaxwell(mwcallback);
ok = scene.readMXS(mxsList);
sceneMaterials = scene.getMaterialNames();
materialcount = int(scene.getMaterialsCount()[0])
if os.path.isfile(self.input_mxs_scene.text()):
for name in sceneMaterials:
scenematerial = scene.getMaterial(name)

Answer 1

problem solved;
i use python 3.5.4 and pyqt 5.9
now even i use read(file) or read(str(file)) don't give any error.
and i find that with pyqt5 it need new arrangement of some lines in the code.
i modify the code and it work :
mxsList = self.input_mxs_scene.text()
scene = Cmaxwell(mwcallback)
materialcount = int(scene.getMaterialsCount()[0])
if not len(inPath) == 0:
if os.path.isfile(self.input_mxs_scene.text()):
ok = scene.readMXS(mxsList)
sceneMaterials = scene.getMaterialNames()
if not len(mxsList) == 0:
for name in sceneMaterials:
scenematerial = scene.getMaterial(name)
# #print scenematerial
self.mxm_list.addItem(name)
i also add : from PyQt5.QtCore import *
that solve other problem with reading media files
after many tries with different versions of python and pyqt5 ; the best versions works well together , python 2.7.9 and pyqt5 from github :
PyQt 5.7.1 for Python 2.7