title: what are the possible permutations of 8 digits
body: <p>I need to know what are the possible permutations of 8 digits following the rules of my python code:</p>
  
  <pre><code>import itertools
  import time
  import string
  
  numbers = set(range(10))
  letters = set(string.ascii_letters)
  mylist=[]
  start=time.time()
  
  comb = ([x for x in itertools.combinations([0,1,2,3,4,5,6,7,8,9,'a','b','c','d','e','f','g','h','i','j','k','l','m','n','o','p','q','r','s','t','u','v','w','x','y','z','A','B','C','D','E','F','G','H','I','J','K','L','M','N','O','P','Q','R','S','T','U','V','W','X','Y','Z'], 8)
         if set(x) &amp; letters and set(x) &amp; numbers])
  
  f=open("data.txt","w")
  f.write("%s" % comb)
  f.close()
  
  end=time.time()
  diff=end-start
  
  print ("Se obtuvieron {} combinaciones.".format(len(comb)))
  print ("En un tiempo total de:",diff,"segundos")
  </code></pre>