Generate Random variates with a certain Probability density function by python

I want to generate a random variate with maxwell energy distribution. The probablily density function is like :

def f(ene):  
     le=3  
     return 2(ene/pi/le**3)*np.exp(-ene/le)

I would like to generate 10000 samples like

f.rvs(scale,size)

How could I do it?