Use repr for __repr__ and str for __str__ Implementations

[popescu-v]

Description

Currently, str is used in the __repr__ implementations of some custom objects, such as Dataset and some concrete implementations of the DatasetTable abstract base class.

However, repr and str do not have the same semantics and are thus not interchangeable by default: repr is low-level and unambiguous, whereas str is readable but potentially ambiguous.

Questions/Ideas

• Revisit all __repr__ and __str__ implementations in the code base and make sure the proper semantics are preserved when using the Python repr and str builtins therein.
  • Case when semantics should not be preserved should be clearly commented.