just for better readability:
* chain comparison statement when appropriate
* do not use f-string when there are no place holders
* use list comprehension when initializing a set
* remove unused import statement
* move import statement of the standard library before
those which import the 3rd-party modules
* put two empty lines in-between top-level functions.
this is recommended by PEP8.
* remove the extraneous spaces around `=` in parameter
list.
* remove the extraneous spaces in a list like `[ 1, 2, 3 ]`
so it looks like `[1, 2, 3]`.
Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>
Closesscylladb/scylladb#21561