Error Finding

[Rakib-Hasan031]

code:
sample=["Iphone is not a bad phone"]
sample=tfidf.transform(sample).toarray()
#print(clf.predict(sample))
sentiment=(clf.predict(sample))
if 0.5<=sentiment<=1 :
print("This is a positive sentence",sentiment)
else:
print("This is a negetive sentence",sentiment)

Output:
This is a negetive sentence [0]

the sentence is a positive sentence but in the text classifier it removes not and count bad as a negetive word.How can i solve it