NLTK库的data路径问题

问题描述

最近在学习《Python自然语言处理》一书中需要使用到NLTK模块，但是在导入数据时出现了问题。即输入from nltk.book import *时，会出现如下所示的错误：

*** Introductory Examples for the NLTK Book ***
Loading text1, ..., text9 and sent1, ..., sent9
Type the name of the text or sentence to view it.
Type: 'texts()' or 'sents()' to list the materials.
Traceback (most recent call last):
  File "D:\Anaconda3\lib\site-packages\nltk\corpus\util.py", line 80, in __load
    try: root = nltk.data.find('{}/{}'.format(self.subdir, zip_name))
  File "D:\Anaconda3\lib\site-packages\nltk\data.py", line 653, in find
    raise LookupError(resource_not_found)
LookupError: 
**********************************************************************
  Resource 'corpora/gutenberg.zip/gutenberg/' not found.  Please
  use the NLTK Downloader to obtain the resource:  >>>
  nltk.download()
  Searched in:
    - 'F:\\Demo_files\\PCB/nltk_data'
    - 'C:\\nltk_data'
    - 'D:\\nltk_data'
    - 'E:\\nltk_data'
    - 'D:\\Anaconda3\\nltk_data'
    - 'D:\\Anaconda3\\lib\\nltk_data'
    - 'C:\\Users\\Spico\\AppData\\Roaming\\nltk_data'
**********************************************************************
During handling of the above exception, another exception occurred:
Traceback (most recent call last):
  File "D:\Anaconda3\lib\site-packages\IPython\core\interactiveshell.py", line 2862, in run_code
    exec(code_obj, self.user_global_ns, self.user_ns)
  File "", line 1, in 
    from nltk.book import *
  File "D:\PyCharm\PyCharm 2017.3.1\helpers\pydev\_pydev_bundle\pydev_import_hook.py", line 20, in do_import
    module = self._system_import(name, *args, **kwargs)
  File "D:\Anaconda3\lib\site-packages\nltk\book.py", line 20, in 
    text1 = Text(gutenberg.words('melville-moby_dick.txt'))
  File "D:\Anaconda3\lib\site-packages\nltk\corpus\util.py", line 116, in __getattr__
    self.__load()
  File "D:\Anaconda3\lib\site-packages\nltk\corpus\util.py", line 81, in __load
    except LookupError: raise e
  File "D:\Anaconda3\lib\site-packages\nltk\corpus\util.py", line 78, in __load
    root = nltk.data.find('{}/{}'.format(self.subdir, self.__name))
  File "D:\Anaconda3\lib\site-packages\nltk\data.py", line 653, in find
    raise LookupError(resource_not_found)
LookupError: 
**********************************************************************
  Resource 'corpora/gutenberg' not found.  Please use the NLTK
  Downloader to obtain the resource:  >>> nltk.download()
  Searched in:
    - 'F:\\Demo_files\\PCB/nltk_data'
    - 'C:\\nltk_data'
    - 'D:\\nltk_data'
    - 'E:\\nltk_data'
    - 'D:\\Anaconda3\\nltk_data'
    - 'D:\\Anaconda3\\lib\\nltk_data'
    - 'C:\\Users\\Spico\\AppData\\Roaming\\nltk_data'
**********************************************************************

之前曾经使用过nltk库，并且通过nltk.download() 工具下载过相关的语料，加之错误信息的提示，所以考虑到要从路径方面解决。

解决办法

在导入nltk.book 前，先使用如下指令将data路径导入：

from nltk import data
data.path.append(r"F:\nltk_data") # 这里的路径需要换成自己数据文件下载的路径

问题即可解决。网上查到的资料还有修改系统环境变量的方法，但是本人尝试后并未发现有效。