pyqtgraph is installed but isn't recognized when I import it

Question

I am trying to run this code that visualizes audio waveforms and their fourier transforms https://github.com/markjay4k/Audio-Spectrum-Analyzer-in-Python/commit/ff9caf4156b7a8c039d8beba987f93566a6aace0

It requires numpy, PyQt, and pyqtgraph. When I run it, I get an error right of the bat.

from pyqtgraph.Qt import QtGui, QtCore

ModuleNotFoundError: No module named 'pyqtgraph'

I know I installed this, because I have pyqtgraph in my site-packages folder. I used pip install pyqtgraph to install it, and if I run the command again, it confirms that the install has already been performed.

What am I doing wrong? Is there some version incompatability? Do I need to do a little dance in my PJs to get it working? I'm not sure.

Answer 1

This normally happens when you try to use a library in either a different Python version, virtual environment, or platform. I'd troubleshoot as follows:

• Check for typos and that you are using the correct way to import the library and submodules.
• If you have multiple Python versions, make sure you are running on the one where the library is installed.
• If you use both pip and conda, make sure you are running the code on the correct platform.
• If both the Python version and platform are ok, check you are working in the same virtual environment where you installed the library in question. I think this is the most probable cause.

You can find plenty of tutorials on how to check all the above. If nothing works, you can try uninstalling and reinstalling.