code: def mae(pred, true):
      return np.mean(np.abs(pred - true))
  
file_path: PGL/examples/kddcup2021/PCQM4M/ensemble/ensemble.py
imports: import os
  import os.path
  import glob
  import pickle
  import numpy
  import pandas
  import sklearn
  import sklearn.linear_model
  import torch
label_desc: Use image node_id 1 for calling a global function with example usage: mae(pred, true) and returns: np