RuntimeError: the sip module implements API v11.0 to v11.2 but the PyQt5.QtCore module requires API v11.3

I recently installed PyQt4 onto my system and started doing some basic tasks (course work), it worked fine.

Then, after some days, I was trying to work with matplotlib.

When I tried import matplotlib.pyplot as plt,I get the following error:

Traceback (most recent call last):
  File "C:UsersuserDesktopConfusion.py", line 1, in <module>
    import matplotlib.pyplot as plt
  File "C:Program FilesAnaconda3libsite-packagesmatplotlibpyplot.py", line 114, in <module>
    _backend_mod, new_figure_manager, draw_if_interactive, _show = pylab_setup()
  File "C:Program FilesAnaconda3libsite-packagesmatplotlibbackends__init__.py", line 32, in pylab_setup
    globals(),locals(),[backend_name],0)
  File "C:Program FilesAnaconda3libsite-packagesmatplotlibbackendsbackend_qt5agg.py", line 16, in <module>
    from .backend_qt5 import QtCore
  File "C:Program FilesAnaconda3libsite-packagesmatplotlibbackendsbackend_qt5.py", line 27, in <module>
    import matplotlib.backends.qt_editor.figureoptions as figureoptions
  File "C:Program FilesAnaconda3libsite-packagesmatplotlibbackendsqt_editorfigureoptions.py", line 17, in <module>
    import matplotlib.backends.qt_editor.formlayout as formlayout
  File "C:Program FilesAnaconda3libsite-packagesmatplotlibbackendsqt_editorformlayout.py", line 58, in <module>
    from matplotlib.backends.qt_compat import QtGui, QtWidgets, QtCore
  File "C:Program FilesAnaconda3libsite-packagesmatplotlibbackendsqt_compat.py", line 127, in <module>
    from PyQt5 import QtCore, QtGui, QtWidgets
RuntimeError: the sip module implements API v11.0 to v11.2 but the PyQt5.QtCore module requires API v11.3
[Finished in 1.9s]

I thought that the problem is with the installation of PyQt4 while I already had PyQt5, but thiswebsite says that they can work properly together without any problem, provided the sip is of same version for both.

The problem seems to be coming from sip.

I followed the steps given here : PyQt5 – SIP API 10 level error. API 11 required

1. When I run import sip and then
   print(sip, sip.SIP_VERSION_STR)

   I get the following:

   4.16.9

2. Then when I run sip -V in the command prompt, I get 4.18.

I clearly see that there is in the sip module.

All I want to ask is, how do I solve this problem?

I am on a Windows 8 64 bit system, using Anaconda3

Any help is appreciated. 🙂