Weighted random sample without replacement in python

Question

I need to obtain a k-sized sample without replacement from a population, where each member of the population has a associated weight (W).

Numpy\'s rando

Answer 1

You can use np.random.choice with replace=False as follows:

np.random.choice(vec,size,replace=False, p=P)

where vec is your population and P is the weight vector.

For example:

import numpy as np
vec=[1,2,3]
P=[0.5,0.2,0.3]
np.random.choice(vec,size=2,replace=False, p=P)