title: How to execute python program and save output in different file names automatically
body: <p>I have a Python program which processes images and save the resulting output to a file. I am receiving the input and output file names via console using input(). But I want to save the output automatically with the file name as something like "input_file_name_out". Note the string "_out" attached to the input file name</p>
  
  <p>This will help me get user input only for Input file names thereby saving little time for the user since he doesn't need to think everytime what should be the output file name</p>
  
  <p><strong>Sample code snippet</strong></p>
  
  <pre><code>if __name__ == "__main__":
  
      in_file = input()
      out_file = input()
  
      processed = process_image(in_file,out_file)
  </code></pre>
  
  <p><strong>Expected code snippet</strong></p>
  
  <pre><code>if __name__ == "__main__":
  
      in_file = input()
      # out_file = input() ------Not getting the file name from user thereby supplying only one argument to the below function
  
          processed = process_image(in_file)
  
  # And within the function
  def process_image(img):
      .
      .
      .
      out_file = img+"_out.jpg" ##### What should come here to achieve my requirement ########
      cv2.imwrite(out_file,processed_image)
  </code></pre>