csvkit 笔记 （引用）

csvkit :  https://csvkit.readthedocs.org/en/0.9.0/

csvstack 添加列，csvcut 抽取列

$ HEADER="$(head -n 1 wine-red-clean.csv),type"
$ csvstack -g red,white -n type wine-{red,white}-clean.csv |
> csvcut -c $HEADER > wine-both-clean.csv

csvstack 在wine-{red,white}-clean.csv数据添加一个新列type，分别取值为red,white

csvcut 指定最终提取的列数据名称

统计sum

$ cat *.csv | header -a borough,count |
> Rio -e 'aggregate(count ~ borough, df, sum)' |
> csvsort -rc count | csvlook

$ cat *.csv | header -a borough,count |
> csvsql --query 'SELECT borough, SUM(count) AS count FROM stdin '\
> 'GROUP BY borough ORDER BY count DESC' | csvlook