title: Attribute error when generating random numbers in Python
body: <p>I asked a similar question regarding this same piece of code earlier but once again I have found myself stuck. Particularly on the generation of a license plate containing two letters, two numbers, and then two letters. I hope that this question isn't a duplicate but in this circumstance I am very stuck with what to do, this is the code so far and I hope you can identify where I am going wrong:</p>
  
  <pre><code>from datetime import date, datetime, time, timedelta
  import time, string
  from random import uniform, random
  
  def timeDelta():
      print("Average Speed Checker")
      start = (input("Car has passed Cam1: "))
      licensePlate = str(firstLetters + randomNumber + " " + secondLetters)
      print(licensePlate)
      if start in ("y"):
          camInput1 = datetime.now()
          print(camInput1)
          print("Car is travelling...")
          time.sleep(1)
          print("Car is travelling...")
          time.sleep(1)
          print("Car has passed cam2")
          camInput2 = camInput1 + timedelta(seconds = uniform(5, 10))
          timeDelta = camInput2 - camInput1
          distance = 200
          duration = timeDelta.total_seconds()
          print("Time Delta is equal to: {0}".format(duration))
          speedCarMs = distance/duration
          print("Car is travelling in m/s at: {0}".format(speedCarMs))
          speedCarMph = 2.237*speedCarMs
          print("Car is travelling in MPH at: {0}".format(speedCarMph))
          if speedCarMph &gt; 60:
              fileInput:
  
  def possibleNumber():
      possibleNumbers = (1,2,3,4,5,6,7,8,9,0)
      randomNumber = random.sample(possibleNumbers, 2)
  
  def randomLetters1(y):
      return ''.join(random.choice(string.ascii_uppercase) for x in             range(y))
  firstLetters = (randomLetters1(2))
  secondLetters = (randomLetters1(3))
  
  print("Choose which function you want to use: ")
  while True:
      answer = (input("Choice: "))
      if answer in ("speed"):
          timeDelta()
  else:
      print("Invalid response")
  </code></pre>
  
  <p>According to python, the issue is to do with this:</p>
  
  <pre><code>AttributeError: 'builtin_function_or_method' object has no attribute 'choice'
  </code></pre>