Syntax for Piecewise?

[WhiteBlackGoose]

What would be a good syntax for piecewise-defined function? Currently, it's

• Piecewise(a provided b, c provided d) without the otherwise case
• Piecewise(a provided b, c provided d, e) with the otherwise case.

By this time, multiple ideas have been considered:

• a if b else c (but how to expand for more than two cases?)
• (a if b, c if d, ..., e) (but will there be no conflicts in the future?)
• (a if b else c if d else ..., e) (is it readable enough?)
• piecewise((a, b), (c, d), ..., e) (sympy's way)
• if a then b elif c then d ... else e (is it convenient?)

Your ideas are welcomed