How to make a custom kernel for extraction?

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Hello,

I use morphological opening to extract horizontal lines from my image:

<...uploading an image and binarizing it...>    
kernel_2 = np.ones((1,7), np.uint8)
hor_opening = cv2.morphologyEx(binary_img, cv2.MORPH_OPEN, kernel)

It works perfectly, but what should I do to use a kernel that combines ones and zeros? I want to extract from my image all segments that satisfy a following mask: [0, 1, 1, 1, 1, 1, 1, 1, 0]