NumPy's random integer methods can be used for sampling from a set of evenly-spaced real numbers, though it requires a bit of extra work: to pick a number from n evenly-spaced real numbers between a and b (inclusive), use:
In [x]: a + (b-a) * (np.random.random_integers(n) - 1) / (n-1.)
For example to sample from $[\frac{1}{2}, \frac{3}{2}, \frac{5}{2}, \frac{7}{2}]$,
In [x]: a, b, n = 0.5, 3.5, 4
In [x]: a + (b-a) * (np.random.random_integers(n, size=10) - 1) / (n-1.)
array([ 1.5, 0.5, 1.5, 1.5, 3.5, 2.5, 3.5, 3.5, 3.5, 3.5])