title: Tournament Selection on Python
body: <p>How do you implement a Roulette wheel Selection on python so that it shows half of the total population after execution?</p>
  <p>So first I generated a total of 100 random words and specified a certain letter to be counted at the beginning of each word. Afterwards, I am expected to halve the total population(100 words to 50 words) using roulette wheel selection. How do I implement roulette wheel selection using the following code?</p>
  <pre><code>import random
  import numpy as np
  
  def population (length, amount, letter, selection):
      alfa='abcdefghijklmnñopqrstuvwxyz'
      item=[]
      fitness=0
      fitness_it=0
      individual=[]
      individual2=[]
      for i in range (amount):
          words =''.join(random.choices(alfa, k=length))
          aptitude = str(words.count(letter))
          item.append(aptitude + words)
          item = [x.upper() for x in item]
          item.sort(reverse=True)
          fitness = fitness + int(aptitude)
      fitness = fitness/amount
      maxi = item[0]
      print(np.array(item))
      print(maxi[0],round(fitness,2))
  </code></pre>