如何在 Awk 中将具有多个子行项目(来自列)的 CSV 转换为新列?

如何在 Awk 中将具有多个子行项目(来自列)的 CSV 转换为新列?

我有一个 CSV 文件,其一般格式如下图所示。

在该 CSV 中,有多行属于某个列 ( desc),我想提取这些项目并将它们添加到新的name, size, weight, glass分别称为 。我已突出显示(以红色)条目的那些子行项目。

原始结构:

在此输入图像描述

预期结构:

在此输入图像描述


原始 CSV:

page,item,id,desc,price
1,2,F1,Alpha,111.11
1,,,380 x 2280 mm (size),
1,,,Weight: 33.0 kg,
1,,,Glass: AAA,
1,,,XXX,
1,3,F2,Beta,222.22
1,,,880 x 2280 mm (size),
1,,,Weight: 68.4 kg,
1,,,Glass: BBB,
1,,,YYY,
1,4,F3,Gamma,333.33
1,,,1980 x 1580 mm (size),
1,,,Weight: 78.2 kg,
1,,,Glass: CCC,
1,,,XXX,
1,,,YYY,
1,,,ZZZ,

预期生成的 CSV:

page,item,id,name,size,weight,glass,price
1,2,F1,Alpha,380 x 2280,33.0,AAA,111.11
1,3,F2,Beta,880 x 2280,68.4,BBB,222.22
1,4,F3,Gamma,1980 x 1580,78.2,CCC,333.33

在哪里姓名将取代第一行的位置描述


更新:

在某些条件下,某些 Awk 解决方案可能适用于上述内容,但在添加第四项时会失败。要进行全面测试,请考虑将其添加到上面:

1,7,F4,Delta,111.11
1,,,11 x 22 mm (size),
1,,,Weight: 33.0 kg,
1,,,Glass: DDD,
1,,,Random-1,

所以3个要点:

  • 列中子行的数量desc可以变化。
  • 之后的任何子行Glass:...都应被忽略。
  • 可能有项目没有任何子行desc列中,它们也应该被忽略。

问:如何使用以下命令将这些子行重新映射到新列中awk
(或者是否有更合适的工具在 bash 中执行此操作?)

可能相关(但不是很有帮助)的问题:

答案1

awk 'BEGIN{ FS=OFS=","; print "page,item,id,name,size,weight,glass,price" }
    $2!=""{ price=$5; data=$1 FS $2 FS $3 FS $4; desc=""; c=0; next }
          { gsub(/ ?(mm \(size\)|Weight:|kg|Glass:) ?/, "") }
    ++c<=3{ desc=(desc==""?"":desc OFS) $4; next }
    data  { print data, desc, price; data="" }
' infile

包括解释:

awk 'BEGIN{ FS=OFS=","; print "page,item,id,name,size,weight,glass,price" }
     #this block will be executed only once before reading any line, and does: 
            #set FS (Field Separator), OFS (Output Field Separator) to a comma character
            #print the "header" line  ....

    $2!=""{ price=$5; data=$1 FS $2 FS $3 FS $4; desc=""; c=0; next }
    #this blocks will be executed only when column#2 value was not empty, and does:
            #backup column#5 into "price" variable
            #also backup columns#1~4 into "data" variable
            #reset the "desc" variable and also counter variable "c"
            #then read next line and skip processing the rest of the code 

          { gsub(/ ?(mm \(size\)|Weight:|kg|Glass:) ?/, "") }
            #this block runs for every line and replace strings above with empty string

    ++c<=3{ desc=(desc==""?"":desc OFS) $4; next }
    #this block runs at most 3reps and 
           #joining the descriptions in column#4 of every line
           #and read the next line until counter var "c" has value <=3 

     data { print data, desc, price; data="" }
     #if "data" variable has containing any data, then
           #print the data, desc, price and empty "data" variable 
' infile 

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