如何从制表符分隔文本文件中提取唯一单词列表？

Question

给定如下制表符分隔的文件：

$ head train.txt 
The Fulton County Grand Jury said Friday an investigation of Atlanta's recent primary election produced `` no evidence '' that any irregularities took place .  AT NP-TL NN-TL JJ-TL NN-TL VBD NR AT NN IN NP$ JJ NN NN VBD `` AT NN '' CS DTI NNS VBD NN .
The jury further said in term-end presentments that the City Executive Committee , which had over-all charge of the election , `` deserves the praise and thanks of the City of Atlanta '' for the manner in which the election was conducted . AT NN RBR VBD IN NN NNS CS AT NN-TL JJ-TL NN-TL , WDT HVD JJ NN IN AT NN , `` VBZ AT NN CC NNS IN AT NN-TL IN-TL NP-TL '' IN AT NN IN WDT AT NN BEDZ VBN .
The September-October term jury had been charged by Fulton Superior Court Judge Durwood Pye to investigate reports of possible `` irregularities '' in the hard-fought primary which was won by Mayor-nominate Ivan Allen Jr. . AT NP NN NN HVD BEN VBN IN NP-TL JJ-TL NN-TL NN-TL NP NP TO VB NNS IN JJ `` NNS '' IN AT JJ NN WDT BEDZ VBN IN NN-TL NP NP NP .
`` Only a relative handful of such reports was received '' , the jury said , `` considering the widespread interest in the election , the number of voters and the size of this city '' .   `` RB AT JJ NN IN JJ NNS BEDZ VBN '' , AT NN VBD , `` IN AT JJ NN IN AT NN , AT NN IN NNS CC AT NN IN DT NN '' .
The jury said it did find that many of Georgia's registration and election laws `` are outmoded or inadequate and often ambiguous '' .  AT NN VBD PPS DOD VB CS AP IN NP$ NN CC NN NNS `` BER JJ CC JJ CC RB JJ '' .
It recommended that Fulton legislators act `` to have these laws studied and revised to the end of modernizing and improving them '' .  PPS VBD CS NP NNS VB `` TO HV DTS NNS VBN CC VBN IN AT NN IN VBG CC VBG PPO '' .
The grand jury commented on a number of other topics , among them the Atlanta and Fulton County purchasing departments which it said `` are well operated and follow generally accepted practices which inure to the best interest of both governments '' . AT JJ NN VBD IN AT NN IN AP NNS , IN PPO AT NP CC NP-TL NN-TL VBG NNS WDT PPS VBD `` BER QL VBN CC VB RB VBN NNS WDT VB IN AT JJT NN IN ABX NNS '' .
Merger proposed NN-HL VBN-HL
However , the jury said it believes `` these two offices should be combined to achieve greater efficiency and reduce the cost of administration '' .    WRB , AT NN VBD PPS VBZ `` DTS CD NNS MD BE VBN TO VB JJR NN CC VB AT NN IN NN '' .
The City Purchasing Department , the jury said , `` is lacking in experienced clerical personnel as a result of city personnel policies '' .    AT NN-TL VBG-TL NN-TL , AT NN VBD , `` BEZ VBG IN VBN JJ NNS CS AT NN IN NN NNS NNS '' .

只有第一列（由制表符分隔）很重要，我想从第一列中提取唯一的单词列表（包括标点符号）并输出到一个文件。假设单词之间用空格隔开，即：

$ head train.txt | cut -f1 
The Fulton County Grand Jury said Friday an investigation of Atlanta's recent primary election produced `` no evidence '' that any irregularities took place .
The jury further said in term-end presentments that the City Executive Committee , which had over-all charge of the election , `` deserves the praise and thanks of the City of Atlanta '' for the manner in which the election was conducted .
The September-October term jury had been charged by Fulton Superior Court Judge Durwood Pye to investigate reports of possible `` irregularities '' in the hard-fought primary which was won by Mayor-nominate Ivan Allen Jr. .
`` Only a relative handful of such reports was received '' , the jury said , `` considering the widespread interest in the election , the number of voters and the size of this city '' .
The jury said it did find that many of Georgia's registration and election laws `` are outmoded or inadequate and often ambiguous '' .
It recommended that Fulton legislators act `` to have these laws studied and revised to the end of modernizing and improving them '' .
The grand jury commented on a number of other topics , among them the Atlanta and Fulton County purchasing departments which it said `` are well operated and follow generally accepted practices which inure to the best interest of both governments '' .
Merger proposed
However , the jury said it believes `` these two offices should be combined to achieve greater efficiency and reduce the cost of administration '' .
The City Purchasing Department , the jury said , `` is lacking in experienced clerical personnel as a result of city personnel policies '' .

$ head train.txt | cut -f2 
AT NP-TL NN-TL JJ-TL NN-TL VBD NR AT NN IN NP$ JJ NN NN VBD `` AT NN '' CS DTI NNS VBD NN .
AT NN RBR VBD IN NN NNS CS AT NN-TL JJ-TL NN-TL , WDT HVD JJ NN IN AT NN , `` VBZ AT NN CC NNS IN AT NN-TL IN-TL NP-TL '' IN AT NN IN WDT AT NN BEDZ VBN .
AT NP NN NN HVD BEN VBN IN NP-TL JJ-TL NN-TL NN-TL NP NP TO VB NNS IN JJ `` NNS '' IN AT JJ NN WDT BEDZ VBN IN NN-TL NP NP NP .
`` RB AT JJ NN IN JJ NNS BEDZ VBN '' , AT NN VBD , `` IN AT JJ NN IN AT NN , AT NN IN NNS CC AT NN IN DT NN '' .
AT NN VBD PPS DOD VB CS AP IN NP$ NN CC NN NNS `` BER JJ CC JJ CC RB JJ '' .
PPS VBD CS NP NNS VB `` TO HV DTS NNS VBN CC VBN IN AT NN IN VBG CC VBG PPO '' .
AT JJ NN VBD IN AT NN IN AP NNS , IN PPO AT NP CC NP-TL NN-TL VBG NNS WDT PPS VBD `` BER QL VBN CC VB RB VBN NNS WDT VB IN AT JJT NN IN ABX NNS '' .
NN-HL VBN-HL
WRB , AT NN VBD PPS VBZ `` DTS CD NNS MD BE VBN TO VB JJR NN CC VB AT NN IN NN '' .
AT NN-TL VBG-TL NN-TL , AT NN VBD , `` BEZ VBG IN VBN JJ NNS CS AT NN IN NN NNS NNS '' .

我可以这样做：

$ python
>>> fout = open('word.dict', 'w')                                                                                                                                     
>>> fout.write('\n'.join(list(set(zip(*[line.split('\t')[0].lower().split() for line in open('train.txt')])[0]))))
>>> exit()
$ head word.dict
trenton
brevet
secondly
fig.
magnetic
doubts
monte
elisabeth
four
facilities

但是有没有办法在shell/bash中提取相同的单词列表？

Answer 1

我不知道标签在您发布的示例输入中的位置，因此这是未经测试的，但应该做您想要的：

awk '{sub(/\t.*/,""); for (i=1; i<=NF; i++) if (!seen[tolower($i)]++) print $i}' file

或者如果您希望所有输出都用小写：

awk '{sub(/\t.*/,""); $0=tolower($0); for (i=1; i<=NF; i++) if (!seen[$i]++) print $i}' file