title: Raspberry pi python spi.open error (FileNotFoundError)
body: <p>I want to use Raspberry pi to programming a chip in python language. However, the spi.open(1,0) function doesn't work. Here is the first few lines of my code:</p>
  
  <pre><code>import spidev
  from time import sleep
  spi = spidev.SpiDev()
  spi.open(1,0)
  </code></pre>
  
  <p>the error appears when I run the code above</p>
  
  <p><img src="https://i.stack.imgur.com/ra0zN.jpg" alt=""></p>
  
  <p>I am sure the spidev package has been installed while the spi interface has been enabled. I have tried to use other bus/device such as spi.open(0,0) but the same error shows again. I have also tried to modify the config file and it doesn't work as the file can't be changed... Could anyone please help me on this problem? many thanks.</p>