code: def population_stability_index(po, qo):
      epsilon = 10e-6
      p = po.copy()
      q = qo.copy()
      p += epsilon
      q += epsilon
      return np.sum((p - q) * np.log(p / q))
  
file_path: popmon/popmon/analysis/comparison/comparisons.py
imports: import numpy
  from scipy import stats
  from popmon.base.registry import Registry
label_desc: Use image node_id 2 for calling a global function with example usage: population_stability_index(po, qo) and returns: np