I just bought a PiGlow and a Pibrella, and I was curious how it worked. I imported a few Python scripts from this and this link, but none of the scripts does work. When I run one of the scripts, I get the error:

Traceback (most recent call last):
  File ''/home/pi/piglowtest3.py'', line 1 in <module>
    from piglow import PiGlow
ImportError: No module named 'piglow' 

I get the same error with the Pibrella, but then is it like this:

Traceback (most recent call last):
  File ''/home/pi/pibrellatest1.py'', line 1 in <module>
    import pibrella
ImportError: No module named 'pibrella' 

I'm using a Raspberry Pi 3B. Is there a change in the modules of Python? Can anybody help me?

Thanks in advance.