问如何改进knn模型？

EN

import pandas as pd
from sklearn.model_selection import train_test_split
from sklearn.preprocessing import MinMaxScaler
from sklearn.neighbors import KNeighborsClassifier
from sklearn.metrics import confusion_matrix, accuracy_score, f1_score
from sklearn.model_selection import GridSearchCV

heart_disease = pd.read_csv('heart_disease.csv', sep=';', decimal=',')
y = heart_disease['heart_disease']
X = heart_disease.drop(["heart_disease"], axis=1)

correlation_matrix = heart_disease.corr()
X_train, X_test, y_train, y_test = train_test_split(X, y, test_size=0.3, random_state=123)

scaler = MinMaxScaler(feature_range=(-1,1))

X_train = scaler.fit_transform(X_train)
X_test = scaler.transform(X_test)

knn_3 = KNeighborsClassifier(3, n_jobs = -1)
knn_3.fit(X_train, y_train)
y_train_pred = knn_3.predict(X_train)
labels = ['0', '1']

print('Training set')
print(pd.DataFrame(confusion_matrix(y_train, y_train_pred), index = labels, columns = labels))
print(accuracy_score(y_train, y_train_pred))
print(f1_score(y_train, y_train_pred))

y_test_pred = knn_3.predict(X_test)

print('Test set')
print(pd.DataFrame(confusion_matrix(y_test, y_test_pred), index = labels, columns = labels))
print(accuracy_score(y_test, y_test_pred))
print(f1_score(y_test, y_test_pred))

hyperparameters = {'n_neighbors' : range(1, 15), 'weights': ['uniform','distance']}

knn_best = GridSearchCV(KNeighborsClassifier(), hyperparameters, n_jobs = -1, error_score = 'raise')
knn_best.fit(X_train,y_train)
knn_best.best_params_

y_train_pred_best = knn_best.predict(X_train)
y_test_pred_best = knn_best.predict(X_test)

print('Training set')
print(pd.DataFrame(confusion_matrix(y_train, y_train_pred_best), index = labels, columns = labels))
print(accuracy_score(y_train, y_train_pred_best))
print(f1_score(y_train, y_train_pred_best))

print('Test set')
print(pd.DataFrame(confusion_matrix(y_test, y_test_pred_best), index = labels, columns = labels))
print(accuracy_score(y_test, y_test_pred_best))
print(f1_score(y_test, y_test_pred_best))