Are there any built-in libraries in Python or Numpy to generate random numbers based on various common distributions, such as:
#!/usr/bin/env python
from scipy.stats import bernoulli,poisson,norm,expon
bernoulli, poisson, norm, expon and many others are documented here
print(norm.rvs(size=30))
print(bernoulli.rvs(.3,size=30))
print(poisson.rvs(1,2,size=30))
print(expon.rvs(5,size=30))
All the distributions defined in scipy.stats have a common interface to the pdf, cdf, rvs (random variates). More info here.