examples: Apply suggestions from code review

Co-authored-by: Jack Betteridge <43041811+JDBetteridge@users.noreply.github.com>

Author: George Bisbas

benchmarks/user/advisor/README.md

@@ -57,7 +57,7 @@ advixe-cl --snapshot --project-dir=<advisor-project-name> pack -- /<new-snapshot
 * Running the `tripcounts` analysis is time-consuming, despite starting in paused
   mode. This analysis, together with the `survey` analysis, is necessary to
   generate a roofline. Both are run by `run_advisor.py`.
-* Requires Python3, untested in conda environments
+* Requires Python 3.9 or later, untested in conda environments
 * Currently requires download of repository and running `pip install .`, the scripts
   are currently not included as a package with the user installation of Devito
 

benchmarks/user/advisor/roofline.py

@@ -202,15 +202,15 @@ def roofline(name, project, scale, precision, mode, th):
                         prop={'size': 7}, title='Rooflines')
 
     # saving the chart in PDF format
-    plt.savefig('%s.pdf' % name, bbox_extra_artists=(legend,), bbox_inches='tight')
+    plt.savefig(f'{name}.pdf', bbox_extra_artists=(legend,), bbox_inches='tight')
     figpath = os.path.realpath(__file__).split(os.path.basename(__file__))[0]
-    log('\nFigure saved in %s%s.pdf.' % (figpath, name))
+    log(f'\nFigure saved in {figpath}{name}.pdf.')
 
     # Save the JSON file
     with open('%s.json' % name, 'w') as f:
         f.write(json.dumps(roofline_data))
 
-    log('\nJSON file saved as %s.json.' % name)
+    log(f'\nJSON file saved as {name}.json.')
     log('Done!')