python中的base64到numpy数组

Question

I have a pdf file which I converted into base64 and then decoded it into binary format ie(010101010) like this. But I want this base64 encoded data to be in a NumPy array. So that it represents in raster binary form.

Below is the code I have tried so far. It is giving me into binary numbers but how to convert it into a NumPy 2D array.

with open("sample.pdf", "rb") as pdf_file:
    encoded_string = base64.b64encode(pdf_file.read())
    decoded = base64.decodebytes(encoded_string)
    decoded_binary_val= "".join(["{:08b}".format(x) for x in decoded])
    print(decoded_binary_val)

The result of the same is in (010101010111101011101010111101011111010101011) this format. But I want a NumPy 2D array ie (r*c)

Answer 1

You can do

arr = np.array([c for c in decoded_binary_val])

This will give you a numpy array of strings. If you want numbers you can do:

arr = np.array([int(c) for c in decoded_binary_val])

Edit - Another option:

If you want string values you can also just cast to list, like this:

arr = np.array(list(decoded_binary_val))

But then if you want numbers you probably need to map:

arr = np.array(list(map(int, decoded_binary_val)))

I haven't been able to measure a difference in performance, so you'll have to check with your setup.