'list' object has no attribute 'lower'

# Импортируем библиотеки
from sklearn.feature_extraction.text import CountVectorizer
# преобразование
vectorizer_count = CountVectorizer()
# словарь
vector_bag_of_words = vectorizer_count.fit_transform(corpus)
# Преобразуем слова в вектор на основе обученного CountVectorizer

AttributeError                            Traceback (most recent call last)
<ipython-input-62-58843bccb98e> in <module>
      4 vectorizer_count = CountVectorizer()
      5 # словарь
----> 6 vector_bag_of_words = vectorizer_count.fit_transform(corpus)
      7 # Преобразуем слова в вектор на основе обученного CountVectorizer
 
3 frames
/usr/local/lib/python3.7/dist-packages/sklearn/feature_extraction/text.py in <lambda>(x)
    254 
    255         if self.lowercase:
--> 256             return lambda x: strip_accents(x.lower())
    257         else:
    258             return strip_accents
 
AttributeError: 'list' object has no attribute 'lower'

with open('bd.csv', newline='') as f:
    reader = csv.reader(f)
    corpus = list(reader)

from sklearn.feature_extraction.text import CountVectorizer
vectorizer_count = CountVectorizer(input='filename')
vector_bag_of_words = vectorizer_count.fit_transform(['bd.csv'])