* Fix line endings of empty files

* Use `not in` for membership test

* Remove unused imports

* Fix implicit string concatenation

* Remove python 2 coding statement

* Change python2's Text into str

* Remove useless linebreaks

* Remove useless parentheses

* Use new-style dictionary and set constructors

* There is no more IOError (alias to OSError now)

* Use .format instead of % string interpolation

* Use super() without redundant arguments

* Remove redundant read flag from open

* Avoid building lists unnecessarily

* Use f-strings with python 3.6

* Black reformat
Co-authored-by: Michael Osthege <michael.osthege@outlook.com>