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'; python - Argument passing takes a lot of time - LavOzs.Com

I am trying to use c++ for faster list loop check from python with ctypes. The problem is that making an argument (don't know how to call it...) takes a lot of time, while function itself is very fast

I am passing a big list (image).

arra = cv2.imread('../smthg.jpg').reshape(1000*1000*3)
lib = ctypes.CDLL('./library.so')
lib.function.restype = ndpointer(dtype=ctypes.c_int, shape=(1000*1000*3,))
arr = (ctypes.c_int * len(arra))(*arra) ### very slow (~1.4s)
res = lib.function(arr) ### the function itself
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