try: from array import array except ImportError: print("SKIP") raise SystemExit def test(a): print(a) a.append(1.2) print(len(a), "%.3f" % a[0]) a.append(1) a.append(False) print(len(a), "%.3f %.3f" % (a[1], a[2])) a[-1] = 3.45 print("%.3f" % a[-1]) test(array("f")) test(array("d")) print("{:.4f}".format(array("f", b"\xcc\xcc\xcc=")[0]))