TypeError: 'in

X_review = bow_transformer.transform(X_review)

from sklearn.model_selection import train_test_split
X_train, X_test, y_train, y_test = train_test_split(X_review, y, test_size=0.3, random_state=101)

# Train Model

from sklearn.naive_bayes import MultinomialNB
nb = MultinomialNB()
nb.fit(X_train, y_train)

# Testing the model

predict=nb.predict(X_test)
from sklearn.metrics import confusion_matrix, classification_report
print(confusion_matrix(y_test, predict))
print('\n')
print(classification_report(y_test, predict))

this the code I wanted run as I have to train and test the model. but getting the error. also please explain what is csr_matrix Thank you in advance.