这是可以正常工作的顺序版本：

tail -n +2 movieratings.csv | cut -d "|" -f 1 | sort | uniq | wc -l
tail -n +2 movieratings.csv | cut -d "|" -f 2 | sort | uniq | wc -l
tail -n +2 movieratings.csv | cut -d "|" -f 3 | sort | uniq | wc -l

，以此类推，获得更多的f值。唯一更改的是字段号。允许并行回答问题。

如果您想遍历它们，我尝试了许多以下操作（甚至超出了所示），但没有一个工作正常。在该主机上似乎不允许使用GNU并行，否则我会使用它并已经完成了。它是google colaboratory的主持人。也许有一种方法可以在colab上并行安装GNU，然后这个答案对我来说也是可以接受的，即使对于其余的堆栈溢出也不可行。这是我的问题，我拥有。

for i in {1..1}; do echo $i; done | xargs -L 30 -I x -n 1 -P 8 cut movieratings.csv -d "|" -f x | sort | uniq | wc -l
for i in {1..2}; do echo $i; done | xargs -I xxx -P 8 cut movieratings.csv -d "|" -f xxx | sort | uniq | wc -l
for i in {1..2}; do echo $i; done | xargs -d $'\n' -I xxx -P 8 cut movieratings.csv -d "|" -f xxx | sort | uniq | wc -l
for i in {1..2}; do echo $i; done | xargs -d $'\n' -n 1 -I xxx -P 8 cut -d "|" -f xxx movieratings.csv | sort | uniq | wc -l
for i in {1..2}; do echo $i; done | xargs -n 1 -I xxx -P 8 cut -d "|" -f xxx movieratings.csv | sort | uniq | wc -l
for i in {1..2}; do echo $i; done | xargs -I xxx -P 8 'cut -d "|" -f xxx movieratings.csv' | sort | uniq | wc -l
for i in {1..2}; do echo $i; done | xargs -I xxx -P 8 cut movieratings.csv -d "|" -f xxx | sort | uniq | wc -l
for i in {1..2}; do echo $i; done | xargs -n 1 -I xxx -P 8 cut movieratings.csv -d "|" -f xxx | sort | uniq | wc -l
for i in {1..2}; do echo $i; done | xargs -I xxx -P 8 "cut movieratings.csv -d '|'" -f xxx | sort | uniq | wc -l

这是一些在其上运行命令的示例数据。希望这会有所帮助。

userid|itemid|rating|rating_year|title|unknown|action|adventure|animation|childrens|comedy|crime|documentary|drama|fantasy|film_noir|horror|musical|mystery|romance|scifi|thriller|war|western|movie_year|movie_age|user_age|gender|job|zipcode
196|242|3.0|1997|Kolya (1996)|0|0|0|0|0|1|0|0|0|0|0|0|0|0|0|0|0|0|0|1997|0|49|M|writer|55105
186|302|3.0|1998|L.A. Confidential (1997)|0|0|0|0|0|0|1|0|0|0|1|0|0|1|0|0|1|0|0|1997|1|39|F|executive|00000
22|377|1.0|1997|Heavyweights (1994)|0|0|0|0|1|1|0|0|0|0|0|0|0|0|0|0|0|0|0|1994|3|25|M|writer|40206
244|51|2.0|1997|Legends of the Fall (1994)|0|0|0|0|0|0|0|0|1|0|0|0|0|0|1|0|0|1|1|1994|3|28|M|technician|80525
166|346|1.0|1998|Jackie Brown (1997)|0|0|0|0|0|0|1|0|1|0|0|0|0|0|0|0|0|0|0|1997|1|47|M|educator|55113
298|474|4.0|1998|Dr. Strangelove or: How I Learned to Stop Worrying and Love the Bomb (1963)|0|0|0|0|0|0|0|0|0|0|0|0|0|0|0|1|0|1|0|1963|35|44|M|executive|01581
115|265|2.0|1997|Hunt for Red October,The (1990)|0|1|0|0|0|0|0|0|0|0|0|0|0|0|0|0|1|0|0|1990|7|31|M|engineer|17110
253|465|5.0|1998|Jungle Book,The (1994)|0|0|1|0|1|0|0|0|0|0|0|0|0|0|1|0|0|0|0|1994|4|26|F|librarian|22903
305|451|3.0|1998|Grease (1978)|0|0|0|0|0|1|0|0|0|0|0|0|1|0|1|0|0|0|0|1978|20|23|M|programmer|94086