porting some some R functions to python

port-r-func.py

def lfactorial(n):
  
    from scipy.special import gammaln
  
    return gammaln(n+1)


def lchoose(n, k):
  
    from scipy.special import gammaln
  
    return (gammaln(n+1) - gammaln(n-k+1) - gammaln(k+1))


def sample(x, size, replace=False, prob=None):
  
    import numpy as np
      
    if type(x) == int:
        a = np.arange(1, x+1)
    else:
        a = x
    return np.random.choice(a, size, replace, prob)