Tinh chỉnh max_depth

# Create your housing DMatrix
housing_dmatrix = xgb.DMatrix(data=X,label=y)

# Create the parameter dictionary
params = {"objective":"reg:squarederror"}

# Create list of max_depth values
max_depths = ____
best_rmse = []

# Systematically vary the max_depth
for curr_val in ____:

    params["____"] = ____
    
    # Perform cross-validation
    cv_results = ____
    
    
    
    # Append the final round rmse to best_rmse
    best_rmse.append(cv_results["test-rmse-mean"].tail().values[-1])

# Print the resultant DataFrame
print(pd.DataFrame(list(zip(max_depths, best_rmse)),columns=["max_depth","best_rmse"]))