TypeError: int() argument must be a string, a bytes-like object or a number, not 'NoneType' when using cv2

Question

import cv2
import numpy as np
from os import listdir
from os.path import isfile, join

# Get the training data we previously made
data_path = 'C:\\Users\\hp\\Unlock-Application\\frames'
onlyfiles = [f for f in listdir(data_path) if isfile(join(data_path, f))]

# Create arrays for training data and labels
Training_Data, Labels = [], []

# Open training images in our datapath
# Create a numpy array for training data
for i, files in enumerate(onlyfiles):
    image_path = data_path + onlyfiles[i]
    images = cv2.imread(image_path, cv2.IMREAD_GRAYSCALE)
    Training_Data.append(np.asarray(images, dtype=np.uint8))
    Labels.append(i)

# Create a numpy array for both training data and labels
Labels = np.asarray(Labels, dtype=np.int32)

# Initialize facial recognizer
model = cv2.face.LBPHFaceRecognizer_create()

# NOTE: For OpenCV 3.0 use cv2.face.createLBPHFaceRecognizer()

# Let's train our model 
model.train(np.asarray(Training_Data), np.asarray(Labels))
print(cv2.__version__)
print("Model trained sucessefully")

When I run this code I get this error

File "c:\Users\hp\Unlock-Application\model.py", line 18, in <module>
Training_Data.append(np.asarray(images, dtype=np.uint8))

TypeError: int() argument must be a string, a bytes-like object or a number, not 'NoneType' any guess how to solve this?

Answer 1

I suspect the error originates from this line:

onlyfiles = [f for f in listdir(data_path) if isfile(join(data_path, f))]

You are checking if isfile but instead you should be checking if it's an image i.e if its .png, .jpg, because anything can be a file. The string method endswith() can be used for this.

onlyfiles = [f for f in listdir(data_path) if isfile(join(data_path, f))]

for f in listdir(data_path):
    image_path = os.path.join(data_path, f) 
    if image_path.endswith(('.png', '.jpg', '.jpeg')): # you can add other formats
       images = cv2.imread(image_path, cv2.IMREAD_GRAYSCALE)