for i in range(1,6):
    m = mlr() # Model instance
    # List of explanatory variables
    X = ['X'+str(j) for j in range(i)]
    # Fitting the dataframe by passing on the list
    m.fit_dataframe(X=X,y='y',dataframe=df) 
    print("nRegression model built with feature vector", X)
    print("Metrics are as follows...")
    print("-"*80)
    m.print_metrics()