Article 1. It is not good to eat pizza after midnight
Article 2. I wouldn't survive a day withouth stackexchange
Article 3. All of these are just random phrases
Article 4. To prove if my experiment works.
Article 5. The red dog jumps over the lazy fox

from sklearn.feature_extraction.text import CountVectorizer
vectorizer = CountVectorizer(min_df=1)

n=0
while n < 5:
   n = n + 1
   a = ('Article %(number)s' % {'number': n})
   print(a)
   with open("LISR2.txt") as openfile:
     for line in openfile:
       if a in line:
           X=line
           print(vectorizer.fit_transform(X))

ValueError: Iterable over raw text documents expected, string object received.

X=("It is not good to eat pizza","I wouldn't survive a day", "All of these")

print(vectorizer.fit_transform(X))

(0, 8)  1
(0, 2)  1
(0, 11) 1
(0, 3)  1
(0, 6)  1
(0, 4)  1
(0, 5)  1
(1, 1)  1
(1, 9)  1
(1, 12) 1
(2, 10) 1
(2, 7)  1
(2, 0)  1