import base64


def b64_to_file(b64_string, new_filename):
    """Converts b64 string to image file, saved
    as new_filename

    Args:
        b64_string: string variable containing the image bytes
                    encoded as a base64 string
        new_filename: filepath to save file as

    Returns:
       an image file on the local computer with the path and name
       contained in the new_filename variable
    """
    image_bytes = base64.b64decode(b64_string)
    with open(new_filename, "wb") as out_file:
        out_file.write(image_bytes)
    return None