linting fix

examples/2_Intermediate/boozerQA_ls_mpi.py

@@ -38,7 +38,7 @@
 Surface solves using the BoozerLS approach can be costly, so this script supports distributing the solves 
 across multiple MPI ranks.
 
-You can change the value of nsurfaces below to optimize for nested surfaces and QS on up to 7 surfaces.  The BoozerSurface
+You can change the value of nsurfaces below to optimize for nested surfaces and QS on up to 10 surfaces.  The BoozerSurface
 solves can be distributed to Nranks ranks using:
     mpirun -n Nranks ./boozerQA_ls_mpi.py
 where nsurfaces is the number of surfaces your optimizing on.
@@ -195,7 +195,7 @@ def callback(x):
 MAXITER = 50 if ci else 1e3
 
 res = minimize(fun, dofs, jac=True, method='BFGS', options={'maxiter': MAXITER}, tol=1e-15, callback=callback)
-curves_to_vtk(curves, OUT_DIR + f"curves_opt")
+curves_to_vtk(curves, OUT_DIR + "curves_opt")
 boozer_surface.surface.to_vtk(OUT_DIR + "surf_opt")
 
 proc0_print("End of 2_Intermediate/boozerQA_ls.py")