Strip whitespaces (including newlines) or a set of specified characters
from each string in the array from left and/or right sides.
Parameters
to_strip (str or None, default: None) – Specifying the set of characters to be removed.
All combinations of this set of characters will be stripped.
If None then whitespaces are removed.
side ({"left","right","both"}, default: "left") – Side from which to strip.