Propose adding a delimeter to Column()
rmasci opened this issue · 10 comments
Right now Columns takes an int, and uses strings.Fields to split the line. I'd like to propose we add a delimiter, so that you could parse csv, semicolon, or pipe delimited files. The function would look like this:
func (p *Pipe) Column(col int, d ...string) *Pipe {
var delim string
if len(d) > 0 {
delim = d[0]
}
return p.FilterScan(func(line string, w io.Writer) {
var columns []string
if delim == "" {
columns = strings.Fields(line)
} else {
columns = strings.Split(line, delim)
}
if col > 0 && col <= len(columns) {
fmt.Fprintln(w, columns[col-1])
}
})
}
d is a ...string means it takes 0 or more arguments, so if the user doesn't pass anything it still works maintaining compatibility with existing programs
Ex:
script.Exec(`echo "one two three"`).Columns(2).Stdout()
would still print 2. However
script.Exec(`echo "one,two,three"`).Columns(2, ",").Stdout()
Would also print 2
Sort of a simple change, and it works for a case where I want to parse through comma separated lines. While I think it works, I might not be thinking of a use case where it would break existing code.
What about something like:
script.File("data.csv").Fields(",").Columns(1, 3, 9).Stdout()sounds nice to me if we can extend it to CSVs along with strings, Should I start working on it ?
Very cool! I'm inspired by nushell to think we should have more data-analysis capabilities like this in script. I don't have any concrete suggestions to make at the moment though. Some use cases would be welcome.