Fix Deepsource issues

[DimitriPapadopoulos]

No description provided.

[DimitriPapadopoulos]

Perhaps the list()/set() part is the most debatable. Links to relevant DeepSource.io pages:

• 7. Not using literal syntax to initialize empty list/dict/tuple

  It is relatively slower to initialize an empty dictionary by calling dict() than using the empty literal, because the name dict must be looked up in the global scope in case it has been rebound. Same goes for the other two types — list() and tuple().

• Consider using literal syntax to create the data structure — PTC-W0019

  DESCRIPTION

  Using the literal syntax can give minor performance bumps compared to using function calls to create dict, list and tuple.
  [...]
  This is because here, the name dict must be looked up in the global scope in case it has been rebound. Same goes for the other two types list() and tuple().

I am happy to discard debatable commits - that's actually why I have multiple commits.

[DimitriPapadopoulos]

Some issues, such as list()/set() → []/{}, have been (partially) fixed in #2364.

The remaining issues are less debatable. I would appreciate someone reviewing them.

[larsoner]

Thanks @DimitriPapadopoulos