tokens=nltk.word_tokenize(corpus)
 uni=nltk.ngrams(tokens,1)
 bi=nltk.ngrams(tokens,2)

 countsU={}
 u=collections.Counter(uni)
 b=collections.Counter(bi)

 for i,j in u.most_common():
      countsU[i[0]]=j # 'TOKEN': <NUM>

 countsB = {}
 for i,j in b.most_common():
     countsB[i]=j

t='am'
 print(countsU[t)

Traceback (most recent call last):
   File "test.py", line 45, in <module>
     print(countsU['am'])
 KeyError: 'am'

 Process finished with exit code 1