【error】Resource 'tokenizers/punkt/PY3/english.pickle' not found. Please use the NLTK Downloader to

报错信息：

LookupError: 
**********************************************************************
  Resource 'tokenizers/punkt/PY3/english.pickle' not found.
  Please use the NLTK Downloader to obtain the resource:  >>>
  nltk.download()
  Searched in:
    - '/users4/zsun/nltk_data'
    - '/usr/share/nltk_data'
    - '/usr/local/share/nltk_data'
    - '/usr/lib/nltk_data'
    - '/usr/local/lib/nltk_data'
    - ''
**********************************************************************

改正：

>>> import nltk
>>> nltk.download()
NLTK Downloader
---------------------------------------------------------------------------
    d) Download   l) List    u) Update   c) Config   h) Help   q) Quit
---------------------------------------------------------------------------
Downloader> d


Download which package (l=list; x=cancel)?
  Identifier> l

Collections:
  [-] all-corpora......... All the corpora
  [-] all-nltk............ All packages available on nltk_data gh-pages
                           branch
  [-] all................. All packages
  [-] book................ Everything used in the NLTK Book
  [P] popular............. Popular packages
  [P] tests............... Packages for running tests
  [ ] third-party......... Third-party data packages


([*] marks installed packages; [-] marks out-of-date or corrupt packages;
 [P] marks partially installed collections)


Download which package (l=list; x=cancel)?
  Identifier> all-nltk
    Downloading collection 'all-nltk'

。。。。

       |   Unzipping stemmers/porter_test.zip.
       | Downloading package wmt15_eval to /users4/zsun/nltk_data...
       |   Unzipping models/wmt15_eval.zip.
       | Downloading package mwa_ppdb to /users4/zsun/nltk_data...
       |   Unzipping misc/mwa_ppdb.zip.
       | 
     Done downloading collection all-nltk

成功。