Fix usage of pylint exceptions

[vkucera]

# pylint: disable= exceptions are overused and misused.

• Fix warnings that can be fixed.
• Use the remaining exceptions only within the scope where they are supposed to apply, i.e.

  at the desired block level or at the end of the desired line of code

See documentation and FAQ for more details.

[benedikt-voelkel]

Indeed @vkucera
Thanks for bringing that up!
Maybe some explanation for everyone: pylint can be used to do different kinds of automatic code (quality) checks, varying from layout to some functional checks.
It is super useful to have pylint checking the code so we don't need to all those things by hand. Of course, sometimes, one really wants something to look/work in a very specific way and there are always exceptions to the rules (as usual...): In those cases we use # pyliint: disable=<warning/error-code>
However, overusing/misuse makes the entire pylint business useless, so only disable if you are absolutely certain about it. If not (or you don't understand a certain pylint warning) you can ask me anytime.
Long story short: Whenever you work on a code-snippet in the future, it would be awesome to validate the usage of # pylint: disable= statements