[PyQt] PyQt 5.7: can't import QtCore

[Sibylle Koczian]

Hello,

I just installed PyQt 5.7 using pip on Windows 10, Python 3.5.2, but I 
can't use it:

Python 3.5.2 (v3.5.2:4def2a2901a5, Jun 25 2016, 22:18:55) [MSC v.1900 64 
bit (AMD64)] on win32
Type "copyright", "credits" or "license()" for more information.
 >>> from PyQt5 import QtCore
Traceback (most recent call last):
   File "<pyshell#0>", line 1, in <module>
     from PyQt5 import QtCore
ImportError: DLL load failed: Die angegebene Prozedur wurde nicht 
gefunden. (The specified procedure could not be found)

Importing PyQt5 doesn't help:

 >>> import PyQt5
 >>> xx = PyQt5.QtCore.QCoreApplication()
Traceback (most recent call last):
   File "<pyshell#3>", line 1, in <module>
     xx = PyQt5.QtCore.QCoreApplication()
AttributeError: module 'PyQt5' has no attribute 'QtCore'

Python is installed for all users and it's located in "c:\program 
files\python35". Which hasn't been a problem for PyQt5 5.6.

The installation of 5.7 didn't produce any error messages.

What can I do? Which additional information should I provide?

Thank you for help,
Sibylle