No values is coming during tokenizing (texts_to_sequence) [closed]

Question

from tensorflow.keras.preprocessing.text import Tokenizer
from tensorflow.keras.preprocessing.sequence import pad_sequences
test_sentence1 = "This is the worst flight experience of my life!"
tokenizer = Tokenizer(num_words=5000)
sequences = tokenizer.texts_to_sequences([test_sentence1])
print(sequences)
text = pad_sequences(sequences, maxlen=200)
print(text)

Output: sequences --> [[]]

There is no output is coming when I tokenize with text_to_sequence.