Golang：如何仅读取制表符分隔文件中的特定列？

Question

In Golang do we have a way to read only certain columns like textscan in matlab, e.g.:

txt = textscan(op,'%s%*s%s%*s');

Thanks!

Answer 1

If your file is basically a TSV file (that is, a CSV file with tabs instead of commas), you can make a very simple wrapper around stdlib's csv.Reader:

type FieldsReader struct {
    *csv.Reader
    fields []int
}

func (r *FieldsReader) Read() (record []string, err error) {
    rec, err := r.Reader.Read()
    if err != nil {
        return nil, err
    }

    record = make([]string, len(r.fields))
    for i, f := range r.fields {
        record[i] = rec[f]
    }

    return record, nil
}

Full code and usage example: http://play.golang.org/p/YcwOmsMX2B.