CODEWITHSUNDEEP
csvscriptingtcl
LALITHYA
LALITHYA

Reputation: 21

TCL script to regroup csv file data

I am new to tcl scripting.

I have 2 columns in my CSV file.

Example: My data

A 12
D 18
B 33
A 11
D 49

I would like to extract column 2 values using Column 1 data.

Required output:


A: 12,11
B: 33
D: 18, 49

Can someone please help me to write a tcl script to perform this task? Thank you in advance.

Upvotes: 0

Views: 220

Answers (1)

Donal Fellows
Donal Fellows

Reputation: 137717

This is a very well known problem, and Tcl's dict lappend is exactly the tool you need to solve it (together with csv::split from tcllib to do the parsing of your input data).

package require csv

# Read split and collect
set data {}
while {[gets stdin line] >= 0} {
    lassign [csv::split $line] key value; # You might need to configure this
    dict lappend data $key $value
}

# Write out
puts ""; # Blank header line
dict for {key values} $data {
    puts [format "%s: %s" $key [join $values ", "]]
}

The above is written as a stdin-to-stdout filter. Adapting to work with files is left as an exercise.

Upvotes: 2

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