installing PyQt5 in Windows 7

I wrote a program in Python 3.4 and I want to make a GUI for it. I"ve found that PyQt5 - is the tool for it.

1) I've downloaded and installed a binary package of PyQt5 (http://ift.tt/1aK63Sr).

2) I tried to run this example code in Python:

import sys
from PyQt5.QtWidgets import QApplication, QWidget


if __name__ == '__main__':
    app = QApplication(sys.argv)
    w = QWidget()
    w.resize(250, 150)
    w.move(300, 300)
    w.setWindowTitle('Simple')
    w.show()

    sys.exit(app.exec_())

Python returned en error:

Traceback (most recent call last):
  File "<frozen importlib._bootstrap>", line 2218, in _find_and_load_unlocked
AttributeError: 'module' object has no attribute '__path__'

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "D:\PyQt5.py", line 2, in <module>
    from PyQt5.QtWidgets import QApplication, QWidget
  File "D:\PyQt5.py", line 2, in <module>
    from PyQt5.QtWidgets import QApplication, QWidget
ImportError: No module named 'PyQt5.QtWidgets'; 'PyQt5' is not a package

3) I found an advise to install QT. So, I downloaded and installed QT (http://ift.tt/1E0Ocm1).

4) Then I've uninstalled and installed again a binary package of PyQt5. No results.

Python doesn't return any errors if I run:

import PyQt5

But if I try to run:

from PyQt5.QtWidgets import QApplication, QWidget

It returns the same error as in the beginning.

Traceback (most recent call last):
  File "<frozen importlib._bootstrap>", line 2218, in _find_and_load_unlocked
AttributeError: 'module' object has no attribute '__path__'

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "D:\PyQt5.py", line 2, in <module>
    from PyQt5.QtWidgets import QApplication, QWidget
  File "D:\PyQt5.py", line 2, in <module>
    from PyQt5.QtWidgets import QApplication, QWidget
ImportError: No module named 'PyQt5.QtWidgets'; 'PyQt5' is not a package

What am I doing wrong?