Question

如果第二列( $2=="")为空，则考虑该行，然后将值打印为$1，其余行直到下一个第二列为空($2=="")。然后需要delete第二列为空的所有行( $2=="")

FILE.CSV

Name_Subject,Marks,Desc,Details
Adam,,,
English,10,xxx,xxx
Maths,20,yyy,yyy
Benn,,,
English,10,xxx,xxx
Maths,20,yyy,yyy
Science,30,zzz,zzz
Zak,,,
English,10,xxx,xxx
Maths,20,yyy,yyy

output.csv

Name,Subject,Marks,Desc,Details
Adam,English,10,xxx,xxx
Adam,Maths,20,yyy,yyy
Benn,English,10,xxx,xxx
Benn,Maths,20,yyy,yyy
Benn,Science,30,zzz,zzz
Zak,English,10,xxx,xxx
Zak,Maths,20,yyy,yyy

我尝试过以下命令但没有成功......

awk -F, 'NR==1{print; next} {if($2 == ""){$2=A}} {A=$2} 1' file.csv

修改＃1

实际文件包含，某些行的整行在数据之间是空的。对于此实例，它填充空值但喜欢捕获先前的非空值。

FILE.CSV

Name_Subject,Marks,Desc,Details
Adam,,,
English,10,xxx,xxx
Maths,20,yyy,yyy
Benn,,,
English,10,xxx,xxx
Maths,20,yyy,yyy
Science,30,zzz,zzz
,,,
,,,
History,40,zzz,zzz
Zak,,,
English,10,xxx,xxx
Maths,20,yyy,yyy

输出＃1

Name,Subject,Marks,Desc,Details
Adam,English,10,xxx,xxx
Adam,Maths,20,yyy,yyy
Benn,English,10,xxx,xxx
Benn,Maths,20,yyy,yyy
Benn,Science,30,zzz,zzz
,History,40,zzz,zzz
Zak,English,10,xxx,xxx
Zak,Maths,20,yyy,yyy

Answer 1

$ awk '
    BEGIN  { FS=OFS="," }
    NR==1  { split($1,f,/_/); name=f[1]; $1=f[2] }
    $2=="" { name=$1; next }
    { print name, $0 }
' file
Name,Subject,Marks,Desc,Details
Adam,English,10,xxx,xxx
Adam,Maths,20,yyy,yyy
Benn,English,10,xxx,xxx
Benn,Maths,20,yyy,yyy
Benn,Science,30,zzz,zzz
Zak,English,10,xxx,xxx
Zak,Maths,20,yyy,yyy

Answer 2

短 awk 方法：

awk -F, 'NR==1;$1==""{next}NR>1 && $2==""{ f=$1; next }f{ print f,$0 }' OFS=',' file

输出：

Name_Subject,Marks,Desc,Details
Adam,English,10,xxx,xxx
Adam,Maths,20,yyy,yyy
Benn,English,10,xxx,xxx
Benn,Maths,20,yyy,yyy
Benn,Science,30,zzz,zzz
Benn,History,40,zzz,zzz
Zak,English,10,xxx,xxx
Zak,Maths,20,yyy,yyy

awk从之前的值填充然后删除

2 个答案: