给我写一个根据自己建立的数据集测试人脸识别准确率的python代码

好的，下面是代码：

import face_recognition
import os

known_faces_dir = 'known_faces/'
unknown_faces_dir = 'unknown_faces/'

# Load known faces
known_faces = []
known_names = []

for filename in os.listdir(known_faces_dir):
    image = face_recognition.load_image_file(known_faces_dir + filename)
    encoding = face_recognition.face_encodings(image)[0]
    known_faces.append(encoding)
    known_names.append(os.path.splitext(filename)[0])

# Load unknown faces and test accuracy
num_correct = 0
num_total = 0

for filename in os.listdir(unknown_faces_dir):
    image = face_recognition.load_image_file(unknown_faces_dir + filename)
    encoding = face_recognition.face_encodings(image)[0]
    
    # Compare unknown face with known faces
    results = face_recognition.compare_faces(known_faces, encoding)
    if True in results:
        index = results.index(True)
        print(f"The unknown face '{filename}' belongs to '{known_names[index]}'")
        num_correct += 1
    else:
        print(f"The unknown face '{filename}' cannot be identified")
    
    num_total += 1

# Calculate accuracy
accuracy = num_correct / num_total * 100
print(f"\nAccuracy: {accuracy:.2f}%")

这段代码通过调用 face_recognition 库中的函数，利用已知人脸数据集建立人脸向量并存储，之后通过比对未知人脸向量与已知人脸向量是否具有相似度，从而得出识别准确率。 注：需要先安装 face_recognition 库。