The integral over the pdf is one. You can see this by using numerical integration from scipy
>>> from scipy.integrate import quad
>>> quad(rv.pdf, 0, 1)
(0.9999999999999999, 1.1102230246251564e-14)
or by writing your own ad-hoc integration (with a trapezoidal rule in this example)
>>> x = numpy.linspace(start=0, stop=1, num=201)
>>> (0.5 * rv.pdf(x[0]) + rv.pdf(x[1:-1]).sum() + 0.5 * rv.pdf(x[-1])) / 200.0
1.0000000068732813