本文重點介紹預料庫的一般操作。
1. 使用nltk加載自己的預料庫
1 >>> from nltk.corpus import PlaintextCorpusReader 2 >>> corpus_root=r'D:/00001/2002/Annual_txt' 3 >>> reader=PlaintextCorpusReader(corpus_root, '.*') 4 >>> reader.fileids() 5 ['2001 Business Highlights .txt', 'Back Cover.txt', 'Balance Sheet.txt', 'Cheung Kong Infrastructure Holdings Limited.txt', 'Consolidated Balance Sheet.txt', 'Consolidated Cash Flow Statement.txt', 'C 6 onsolidated Profit & Loss Account .txt', 'Consolidated Statement of Recognised Gains and Losses.txt', 'Contents.txt', 'Corporate Information.txt', 'Cover.txt', 'Development Projects.txt', "Directors' 7 Biographical Information.txt", 'Extracts from Hutchison Whampoa Limited Financial Statements.txt', 'Financial Highlights.txt', 'Group Financial Summary.txt', 'Group Structure.txt', 'Hongkong Electric 8 Holdings Limited.txt', 'Hutchison Whampoa Limited.txt', 'Management Discussion and Analysis.txt', 'Notes to Financial Statements.txt', 'Notice of Annual General Meeting.txt', 'Overseas Properties.txt' 9 , 'Rental Properties.txt', 'Report of the Auditors.txt', 'Report of the Chairman and the Managing Director.txt', 'Report of the Directors.txt', 'Schedule of Major Properties.txt'] 10 >>>
這里將本地'D:/00001/2002/Annual_txt'文件夾作為一個預料庫，操作里面的文件。
2. 預料庫的一般操作
1） fileids(): 獲取預料庫中的文件列表
2） fileids([categories]): 獲取分類對應的語料庫中的文件
3）categories(): 獲取語料庫的分類
4） categories([fileids]): 獲取文件對應的語料庫中的分類
5） raw(): 獲取語料庫中的原始內容
6）raw(fileids=[f1, f2, f3]): 獲取指定文件中的原始內容
7） words(): 獲取整個語料庫中的詞匯
8）words([fileids=[f1, f2, f3]): 獲取指定文件中的詞匯
9） words(categories=[c1, c2]): 獲取指定分類中的詞匯
10） sents(): 獲取整個語料庫中的句子
11）sents([fileids=[f1, f2, f3]): 獲取指定文件中的句子
12） sents(categories=[c1, c2]): 獲取指定分類中的句子
13） abspath(fileid): 獲取指定文件在磁盤上的位置
14） encoding(fileid): 獲取指定文件的文件編碼（如果知道的話）
15） open(fileid): 獲取打開指定語料庫文件的文件流
16）readme(): 獲取語料庫的README文件的內容
1 >>> from nltk.corpus import PlaintextCorpusReader 2 >>> corpus_root=r'D:/00001/2002/Annual_txt' 3 >>> reader=PlaintextCorpusReader(corpus_root, '.*') 4 >>> reader.fileids() 5 ['2001 Business Highlights .txt', 'Back Cover.txt', 'Balance Sheet.txt', 'Cheung Kong Infrastructure Holdings Limited.txt', 'Consolidated Balance Sheet.txt', 'Consolidated Cash Flow Statement.txt', 'C 6 onsolidated Profit & Loss Account .txt', 'Consolidated Statement of Recognised Gains and Losses.txt', 'Contents.txt', 'Corporate Information.txt', 'Cover.txt', 'Development Projects.txt', "Directors' 7 Biographical Information.txt", 'Extracts from Hutchison Whampoa Limited Financial Statements.txt', 'Financial Highlights.txt', 'Group Financial Summary.txt', 'Group Structure.txt', 'Hongkong Electric 8 Holdings Limited.txt', 'Hutchison Whampoa Limited.txt', 'Management Discussion and Analysis.txt', 'Notes to Financial Statements.txt', 'Notice of Annual General Meeting.txt', 'Overseas Properties.txt' 9 , 'Rental Properties.txt', 'Report of the Auditors.txt', 'Report of the Chairman and the Managing Director.txt', 'Report of the Directors.txt', 'Schedule of Major Properties.txt'] 10 >>> reader.categories() 11 Traceback (most recent call last): 12 File "<stdin>", line 1, in <module> 13 AttributeError: 'PlaintextCorpusReader' object has no attribute 'categories' 14 >>> reader.raw()[:100] 15 u'CHEUNG KONG (HOLDINGS) LIMITED\r\n\r\nANNUAL REPORT 2001\r\n\r\n2001 Business Highlights\r\n\r\n4\r\n\r\nJanuary\r\n\r\n' 16 >>> reader.raw(fileids='Balance Sheet.txt')[:100] 17 u'CHEUNG KONG (HOLDINGS) LIMITED\r\n\r\nANNUAL REPORT 2001\r\n\r\nBalance Sheet\r\n\r\nAs at 31st December, 2001\r\n' 18 >>> reader.raw()[:100] 19 u'CHEUNG KONG (HOLDINGS) LIMITED\r\n\r\nANNUAL REPORT 2001\r\n\r\n2001 Business Highlights\r\n\r\n4\r\n\r\nJanuary\r\n\r\n' 20 >>> reader.sents()[:5] 21 [[u'CHEUNG', u'KONG', u'(', u'HOLDINGS', u')', u'LIMITED'], [u'ANNUAL', u'REPORT', u'2001'], [u'2001', u'Business', u'Highlights'], [u'4'], [u'January']] 22 >>> reader.sents(fileids='Balance Sheet.txt')[:5] 23 [[u'CHEUNG', u'KONG', u'(', u'HOLDINGS', u')', u'LIMITED'], [u'ANNUAL', u'REPORT', u'2001'], [u'Balance', u'Sheet'], [u'As', u'at', u'31st', u'December', u',', u'2001'], [u'44']] 24 >>> reader.words(fileids='Balance Sheet.txt')[:5] 25 [u'CHEUNG', u'KONG', u'(', u'HOLDINGS', u')'] 26 >>> reader.words()[:20] 27 [u'CHEUNG', u'KONG', u'(', u'HOLDINGS', u')', u'LIMITED', u'ANNUAL', u'REPORT', u'2001', u'2001', u'Business', u'Highlights', u'4', u'January', u'*', u'Successfully', u'raised', u'a', u'5', u'-'] 28 >>> reader.abspath('Balance Sheet.txt') 29 FileSystemPathPointer('D:\\00001\\2002\\Annual_txt\\Balance Sheet.txt') 30 >>> reader.open('Balance Sheet.txt') 31 <nltk.data.SeekableUnicodeStreamReader object at 0x064822B0>
顯然，自定義的預料庫因為沒有設置categories屬性，所以涉及相關的操作無法進行。