如何在 CSV 中获取字符串，通过字符串名称创建一个新的 CSV 并将该特定行添加到其中？

Question

这是我的 CSV 文件的示例：

04/Feb/2016:06:38:44-0500,ab,3,10,57,200,10254
04/Feb/2016:06:39:07-0500,cd,1,42,168,304,0
04/Feb/2016:06:39:07-0500,ef,1,43,169,304,0
04/Feb/2016:06:39:07-0500,ab,1,43,170,304,0
04/Feb/2016:06:39:07-0500,cd,1,44,171,304,0
04/Feb/2016:06:39:07-0500,ef,1,45,172,304,0

我想在第二列中获取字符串，如果文件不存在则创建类似该字符串的文件，并在文件中添加该特定行。所以像这样：

fetch string in 2nd column -> "ab" -> if file doesnt exist create file called "ab.csv" -> open file and add line "04/Feb/2016:06:38:44-0500,ab,3,10,57,200,10254"
fetch string in 2nd column -> "cd" -> if file doesnt exist create file called "cd.csv" -> open file and add line "04/Feb/2016:06:39:07-0500,cd,1,42,168,304,0"
fetch string in 2nd column -> "ef" -> if file doesnt exist create file called "ef.csv" -> open file and add line "04/Feb/2016:06:39:07-0500,ef,1,43,169,304,0"
fetch string in 2nd column -> "ab" -> if file doesnt exist create file called "ab.csv" -> open file and add line "04/Feb/2016:06:39:07-0500,ab,1,43,170,304,0"
fetch string in 2nd column -> "cd" -> if file doesnt exist create file called "cd.csv" -> open file and add line "04/Feb/2016:06:39:07-0500,cd,1,44,171,304,0"
fetch string in 2nd column -> "ef" -> if file doesnt exist create file called "ef.csv" -> open file and add line "04/Feb/2016:06:39:07-0500,ef,1,45,172,304,0"

结果：

ab.csv:
04/Feb/2016:06:38:44-0500,ab,3,10,57,200,10254
04/Feb/2016:06:39:07-0500,ab,1,43,170,304,0
----------------------------------------------
cd.csv:
04/Feb/2016:06:39:07-0500,cd,1,42,168,304,0
04/Feb/2016:06:39:07-0500,cd,1,44,171,304,0
----------------------------------------------
ef.csv:
04/Feb/2016:06:39:07-0500,ef,1,43,169,304,0
04/Feb/2016:06:39:07-0500,ef,1,45,172,304,0

任何帮助appriciated！

Answer 1

使用 awk

$ awk -F, '{print >> $2".csv"}' file.csv

$ cat ab.csv
04/Feb/2016:06:38:44-0500,ab,3,10,57,200,10254
04/Feb/2016:06:39:07-0500,ab,1,43,170,304,0
$ cat cd.csv
04/Feb/2016:06:39:07-0500,cd,1,42,168,304,0
04/Feb/2016:06:39:07-0500,cd,1,44,171,304,0
$ cat ef.csv
04/Feb/2016:06:39:07-0500,ef,1,43,169,304,0
04/Feb/2016:06:39:07-0500,ef,1,45,172,304,0
$

请记住，尽管真正的 CSV 文件可能在其逗号分隔的字段中包含带引号的逗号- 因此始终建议认真使用适当的 CSV 解析器：请参阅例如如何使用 Perl 读取 CSV 文件？或PyMOTW：逗号分隔值文件。