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如何比较两个不同 csv 文件中的列并替换另一个文件中的列

tag-icon • tag-icon text-processing awk
如何比较两个不同 csv 文件中的列并替换另一个文件中的列

我需要将文件 1 的第 4 列（等级）与文件 2 的第 1 列（等级）相匹配。如果匹配，则将 File1 的第 4 列（等级）替换为 File2 的第 2 列（标记）。如果不匹配，则保留第 4 列（等级）的值不变。

文件1

"RollNo","Name","Age","Grade","Class","Teacher"
"1","Asha","7","A","1","David"
"2","Mona","7","B","1","David"
"3","Sonali","7","C","1","David"
"4","Rani","7","D","1","David"
"5","Raj","7","B","1","David"

文件2

"Grade","Marks"
"A","90"
"B","80"
"C","70"

预期输出：

"RollNo","Name","Age","Grade","Class","Teacher"
"1","Asha","7","90","1","David"
"2","Mona","7","80","1","David"
"3","Sonali","7","70","1","David"
"4","Rani","7","D","1","David"
"5","Raj","7","80","1","David"

您能帮我使用 awk 命令来输出此输出吗？
期待您的回复。

答案1

假设 CSV 中的字段不能包含,s 或换行符 ( \n) 并且您正在运行 Unix shell：

$ awk '
    BEGIN { FS=OFS="," }
    NR==FNR { map[$1] = $2; next }
    (FNR>1) && ($4 in map) { $4 = map[$4] }
1' file2 file1
"RollNo","Name","Age","Grade","Class","Teacher"
"1","Asha","7","90","1","David"
"2","Mona","7","80","1","David"
"3","Sonali","7","70","1","David"
"4","Rani","7","D","1","David"
"5","Raj","7","80","1","David"

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