python error message when loading pickle file

I have the below code :

import numpy as np
import matplotlib.pyplot as plt
import pandas as pd
import re
import nltk
from nltk.corpus import stopwords
from nltk.stem.porter import PorterStemmer
from sklearn.feature_extraction.text import CountVectorizer
from sklearn.model_selection import train_test_split, cross_val_score
from sklearn.utils import shuffle
from sklearn.naive_bayes import GaussianNB
from sklearn.metrics import confusion_matrix
from sklearn.tree import DecisionTreeClassifier
from sklearn.ensemble import RandomForestClassifier
from nltk.tokenize import sent_tokenize, word_tokenize
from sklearn.naive_bayes import MultinomialNB
from sklearn.metrics import accuracy_score
import sklearn.metrics as metrics
import pickle

#%matplotlib inline
import warnings
warnings.filterwarnings('ignore')

stemmer = PorterStemmer()
words = stopwords.words("english")

from sklearn.feature_extraction.text import TfidfVectorizer
vectorizer_tfidf = TfidfVectorizer(stop_words='english', max_df=0.7)

# call and load pickle here
content = pickle.load(open("vectorizer.pk",'rb'))

vectorizer_tfidf = [vectorizer_tfidf]
test_tfIdf = vectorizer_tfidf.transform('processedtext')
test_tfIdf2 = vectorizer_tfidf.transform('processedtext2')

testdata = pd.read_csv('C:\\Users\\joyce\\Desktop\\CR_Summary 08052020.csv', delimiter = ',')
content = pickle.load(open("Pickle_RL_Model.pkl",'rb'))
 
##print (content)    
testdata=testdata.fillna(value='test')

#Array to return prediction
content.predict(testdata)

Error Message:

File "C:/Users/joyce/nltk CR data v3.py", line 42, in test_tfIdf = vectorizer_tfidf.transform('processedtext') AttributeError: 'list' object has no attribute 'transform'

How do I correct this error?