code: def r2_score(df):
      return metrics.r2_score(df.y_true, df.y_pred)
  
file_path: sklearn-evaluation/docs-assets/nb-collection/train.py
imports: import importlib
  from sklearn.datasets import fetch_california_housing
  from sklearn.model_selection import train_test_split
  from sklearn import metrics
  import seaborn
  import pandas
  import numpy
  import matplotlib.pyplot
label_desc: Use image node_id 1 for calling a global function with example usage: r2_score(df) and returns: metrics