Mechanism for nested loops?

[sigvaldm]

Editing all but the last lines in terminal would bloat the library and/or require heavyweight tools such as ncurses, or at least it would require a lot of work. However, it may be possible to use 'compact' for only the innermost loop and 'simple' for others. This should work already. Perhaps it would be possible to separate the loops from one another somehow? Perhaps simply by chaning the format string? This may not even need changes to the library, just an example of how it's done in the documentation.

[sigvaldm]

There could be an argument in the constructor which allows to replace "Step" by e.g. "Timestep" or "Parameter set", etc. the full format string could be replaced by changing it directly (i.e. not in the constructor).