am getting NotFittedError: This MultinomialNB instance is not fitted yet. Call 'fit' with appropriate arguments before using this estimator

Question

my code is import streamlit as st import pickle import string from nltk.corpus import stopwords import nltk from nltk.stem.porter import PorterStemmer

ps = PorterStemmer()

def transform_text(text): text = text.lower() text = nltk.word_tokenize(text)

y = []
for i in text:
    if i.isalnum():
        y.append(i)

text = y[:]
y.clear()

for i in text:
    if i not in stopwords.words('english') and i not in string.punctuation:
        y.append(i)

text = y[:]
y.clear()

for i in text:
    y.append(ps.stem(i))

return " ".join(y)

tfidf = pickle.load(open('vectorizer.pkl','rb')) model = pickle.load(open('model.pkl','rb'))

st.title("Email/SMS Spam Classifier")

input_sms = st.text_area("Enter the message")

if st.button('Predict'):

# 1. preprocess
transformed_sms = transform_text(input_sms)
# 2. vectorize
vector_input = tfidf.transform([transformed_sms])
# 3. predict
result = model.predict(vector_input)[0]
# 4. Display
if result == 1:
    st.header("Spam")
else:
    st.header("Not Spam")