ImportError:没有名为nltk macos的模块

Question

从PythonChatbot开始，使用anaconda遵循教程，无法导入nltk，也无法使用pytorch

import nltk 
#nltk.download('punkt')
from nltk.stem.porter import PorterStemmer
stemmer = PorterStemmer()

def tokenize(sentence):
    return nltk.word_tokenize(sentence)

def stem(word):
    return stemmer.stem(word.lower())



def bag_of_words(tokenized_sentence, all_words):
    pass

a = "How long does shipping take?"
print(a)
a = tokenize(a)
print(a)

尝试导入nltk后出错

(pytorch) jack.s@McUnicorn-Pro-2 Chatbot % python nltk_utils.py
Traceback (most recent call last):
  File "nltk_utils.py", line 1, in <module>
    import nltk 
ImportError: No module named nltk
(pytorch) jack.s@McUnicorn-Pro-2 Chatbot %