from sklearn.ensemble import RandomForestClassifier
estimator = RandomForestClassifier(n_estimators=5, random_state=42)
estimator.fit(X_train, y_train)
for i,e in enumerate(estimator.estimators_):
    n_nodes_ = [t.tree_.node_count for t in estimator.estimators_]
    children_left_ = [t.tree_.children_left for t in estimator.estimators_]
    children_right_ = [t.tree_.children_right for t in estimator.estimators_]
    feature_ = [t.tree_.feature for t in estimator.estimators_]
    threshold_ = [t.tree_.threshold for t in estimator.estimators_]