f strings instead of string addition for compact readable code

[shimwell]

Description

I've noticed the use of + to combine strings together in many places in the code so I wanted to make an example of how we can do this withf strings instead. In this case I think the f string version of code is a little nicer to read than the addition version. I've also made use of +=

Fixes # (issue)

nothing

Additional dependencies introduced.

None

Type of change

Please select what type of change this is.

• refactoring for readability

Other changes

• This change requires a documentation update
• (If Benchmark) This requires additional data that can be obtained from:
  • Benchmark data 1
  • Benchamrk data 2

Testing

Sorry I've checked the output is the same locally but not added tests for this small change

Checklist:

• My code follows the style guidelines of this project
• I have performed a self-review of my code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• General testing
  • New and existing unit tests pass locally with my changes
  • Coverage is >80%