import os


write_path = os.path.join(os.getcwd(), 'task2_data_1.txt')
read_path = os.path.join(os.getcwd(), 'task2_data_2.txt')


if not os.access(write_path, os.F_OK):
    print('Файла "{}" не существует'.format(write_path))
elif not os.access(read_path, os.F_OK):
    print('Файла "{}" не существует'.format(read_path))

elif not os.access(write_path, os.W_OK):
    print('Файл "{}" не доступен для записи'.format(write_path))
elif not os.access(read_path, os.R_OK):
    print('Файл "{}" не доступен для чтения'.format(read_path))

else:
    with open(write_path, 'a') as first, open(read_path) as second:
        first.write('\n\n\n')

        data = second.read(1024)
        first.write(data)
        while data:
            data = second.read(1024)
            first.write(data)

    os.rename('task2_data_1.txt', 'task2_data_all.txt')
    os.remove('task2_data_2.txt')