title: In python, how to generate a random integer in a range, excluding some numbers in a list?
body: <p>For example, at beginning I want generate a random integer from (0,9), </p>
  
  <p>at first time, the program generate 2, then I put 2 in the 'excluding' list, </p>
  
  <p>next time, I need generate a number ranging between 0 to 9, and excluding 2. let's say it the second turn, the program generate 5.</p>
  
  <p>The third turn, I need generate a number ranging from 0 to 9 and excluding 2 and 5.</p>
  
  <p>As the range is very huge (million level), is there any method is efficient?</p>