I have just installed Anaconda 5.2 with Python 3.6 on my windows system. Also installed pyqt5 and pyqt5-tools via pip with administrator privilege. Now when I run pyuic5.exe for
None of the answers above worked for PyQt5 5.13.0 on conda's python 3.6.
With pyqt5 and pyqt5-sip installed just go into python's site-packages and copy sip.so from the PyQt5_sip package to PyQt5 folder (or make a symlink) where the rest of Qt's so modules are.
Seems like a poor decision to pull sip out into a separate package.