python 按顺序读取同一个文件夹下的多图像文件

图像的命名情况如下图所示，以一个字符串和数字组成，希望以1到30的顺序读入文件并以图像矩阵的形式储存在内存中以便后续处理。

使用python编程，借助os库和opencv库。
关键就是使用sort对数字重新排序。

def read_finger_directory(directory_name):
    imglist = os.listdir(r"./"+directory_name)
    array_of_img = []  # this if for store all of the image data
    # print(imglist)
    imglist.sort(key=lambda x: int(x.replace("finger", "").split('.')[0]))
    # print("list_order:", imglist)
    # this loop is for read each image in this foder,directory_name is the foder name with images.
    for filename in imglist:
        # print(filename) #just for test
        # img is used to store the image data
        img = cv2.imread(directory_name + "/" + filename)
        # print(filename)
        array_of_img.append(img)
        # print(img)
        # print(array_of_img)
    return array_of_img