Hi@akhtar,
It seems you don't have this module installed in your system. You can use the below-given command to install this module.
C:\Users\Nadeem Akhter>pip install testfixtures
Collecting testfixtures
Downloading testfixtures-6.14.1-py2.py3-none-any.whl (89 kB)
|████████████████████████████████| 89 kB 141 kB/s
Installing collected packages: testfixtures
Successfully installed testfixtures-6.14.1