Proposed new feature or change:

Currently Polynomial displays as many digits as it can:

x = np.arange(10)
y = 5 * x + 1 + np.random.randn(10)
f = np.polynomial.Polynomial.fit(x, y, 1).convert(); f

𝑥↦0.622720266227418+5.0153841318332235𝑥

It'd be better if it only displayed the number of digits (or less if it can be uniquely represented) configured with np.set_printoptions:

𝑥↦0.62272026+5.01538413𝑥