Why is python throwing error : AttributeError: 'numpy.ndarray' object has no attribute 'append'?

Question

我正在尝试运行以下代码，但 python 抛出错误，即 numpy 没有参数 'append' 的行：“ids.append (id)"

path = [os.path.join("data", f) for f in os.listdir("data")]
faces = []
ids = []

for image in path :
    img = Image.open(image).convert('L')
    nimg = np.array(img, 'uint8')
    id = int(os.path.split(image)[1].split(".")[1])
    faces.append(nimg)
    ids.append(id)
    ids = np.array(ids)
clf = cv2.face.EigenFaceRecognizer_create()
clf.train(faces, ids)
clf.write("classifier.yml")

Answer 1

您在第一次迭代后将 ids 转换为数组。当运行它时，数组中应该只有一项。我会将行 ids = np.array(ids) 移到 for 循环之外。见下文：

path = [os.path.join("data", f) for f in os.listdir("data")]
faces = []
ids = []

for image in path :
    img = Image.open(image).convert('L')
    nimg = np.array(img, 'uint8')
    id = int(os.path.split(image)[1].split(".")[1])
    faces.append(nimg)
    ids.append(id)

ids = np.array(ids)
clf = cv2.face.EigenFaceRecognizer_create()
clf.train(faces, ids)
clf.write("classifier.yml")

如果你想让它真正成为一个数组，你将不得不使用以下样式代码，但列表也应该没问题直到最后。

ids = np.array(ids)
ids = np.append(ids, [id])

Why is python throwing error : AttributeError: 'numpy.ndarray' object has no attribute 'append'?

Why is python throwing error : AttributeError: 'numpy.ndarray' object has no attribute 'append'?

python

opencv

numpy

opencv3.0

numpy-ndarray