input: 
  from collections import Counter
  
  
  def generate_ngrams(text, window_size):
      text = text.lower().split(' ')
      ngrams = []
      for n in range(window_size, len(text)+1):
          for i in range(len(text)-n+1):
              ngrams.append(' '.join(text[i:i+n]))
      return Counter(ngrams)
  
  
  text = "The quick brown fox jumps over the lazy dog"
  window_size = 3
  
  ngrams_count = generate_ngrams(text, window_size)
  
  print('\nNGRAMS COUNT:',ngrams_count)
  
  # Output
  # NGRAMS COUNT: Counter({'the quick brown': 3,
  #            'quick brown fox': 2,
  #            'over the lazy': 1,
  #            'brown fox jumps': 1,
  #            'fox jumps over': 1,
  #            'the lazy dog': 1,
  #            'jumps over the': 1,
  #            'quick brown fox jumps': 1})
  
output:     
      for n in range(window_size, len(text)+1):
          for i in range(len(text)-n+1):
              ngrams.append(' '.join(text[i:i+n]))
      return Counter(ngrams)
  