ln(x) Returns the natural (base e) logarithm of x.

statistics.variance(data, xbar=None) Return the sample variance of data, an iterable of at least two real-valued numbers

class numbers.Rational Subtypes Real and adds numerator and denominator properties, which

random.sample(population, k) Return a k length list of unique elements chosen from the population sequence or set.

cmath.phase(x) Return the phase of x (also known as the argument of x), as a float. phase(x)

is_snan() Return

normalize(x) Reduces x to its simplest form.

adjusted() Return the adjusted exponent after shifting out the coefficient’s rightmost digits until only the lead digit remains:

math.nan A floating-point “not a number” (NaN) value. Equivalent to the output of float('nan').

math.isinf(x) Return True if x is a positive or negative infinity, and False otherwise.