lowercase and remove punctuation from a csv - bash

Question

I have a giant file (6gb) which is a csv and the rows look like so:
"87687","institute Polytechnic, Brazil"
"342424","university of India, India"
"24343","univefrsity columbia, Bogata, Colombia"
and I would like to remove all punctuation and lower the case of second column yielding:
"87687","institutepolytechnicbrazil"
"342424","universityofindiaindia"
"24343","univefrsitycolumbiabogatacolombia"
what would be the most efficient way to do this on the terminal?
Tried:
cat TEXTFILE | tr -d '[:punct:]' > OUTFILE
problem: resultant is not in lowercase and tr seems to act on both columns not just the ssecond.

Answer 1

With a real CSV parser in Perl, the robust/reliable way, using just one process.
As far as it's line by line, the 6GB requirement of file size should not be an issue.
#!/usr/bin/perl
use strict; use warnings; # harness
use Text::CSV; # load the needed module (install it)
use feature qw/say/; # say = print("...\n")
# create an instance of a new CSV parser
my $csv = Text::CSV->new({ auto_diag => 1 });
# open a File Handle or exit with error
open my $fh, "<:encoding(utf8)", "file.csv" or die "file.csv: $!";
while (my $row = $csv->getline ($fh)) { # parse line by line
$_ = $row->[1]; # parse only column 2
s/[\s[:punct:]]//g; # removes both space(s) and punct(s)
$_ = lc $_; # Lower Case current value $_
$row->[1] = qq/"$_"/; # edit changes and (re)"quote"
say join ",", #$row; # display the whole current row
}
close $fh; # close the File Handle
Output
"87687","institutepolytechnicbrazil"
"342424","universityofindiaindia"
"24343","univefrsitycolumbiabogatacolombia"
install
cpan Text::CSV

Answer 2

Here's an approach using xsv and process substitution:
paste -d, \
<(xsv select 1 infile.csv) \
<(xsv select 2 infile.csv | sed 's/[[:blank:][:punct:]]*//g;s/.*/\L&/')
The sed command first removes all blanks and punctuation, then lowercases the entire match.
This also works when the first field contains blanks and commas, and retains quoting where required.

Answer 3

Using sed
$ sed -E ':a;s/([^,]*,)([^ ,]*)[ ,]([[:alpha:]]+)/\1\L\2\3/;ta' input_file
"87687","institutepolytechnicbrazil"
"342424","universityofindiaindia"
"24343","univefrsitycolumbiabogatacolombia

Answer 4

I suggest using this awk solution, which should work with any version of awk:
awk 'BEGIN{FS=OFS="\",\""} {
gsub(/[^[:alnum:]"]+/, "", $2); $2 = tolower($2)} 1' file
"87687","institutepolytechnicbrazil"
"342424","universityofindiaindia"
"24343","univefrsitycolumbiabogatacolombia"
Details:
We make "," input and output field separators in BEGIN block
gsub(/[^[:alnum:]"]+/, "", $2): Strip all non-alphanumeric characters except "
$2 = tolower($2): Lowercase second column

Answer 5

One GNU awk (for gensub()) idea:
awk '
BEGIN { FS=OFS="\"" }
{ $4=gensub(/[^[:alnum:]]/,"","g",tolower($4)) }
1'
This generates:
"87687","institutepolytechnicbrazil"
"342424","universityofindiaindia"
"24343","univefrsitycolumbiabogatacolombia"

Answer 6

Another sed approach -
sed -E 's/ +//g; s/([^"]),/\1/g; s/"([^"]*)"/"\L\1"/g' file
I don't like how that leaves no flexibility, and makes you rewrite the logic if you find something else you want to remove, though.
Another in awk -
awk -F'[", ]+' '
{ printf "\"%s\",\"", $2;
for(c=3;c<=NF;c++) printf "%s", tolower($c);
print "\"";
}' file
This approach lets you define and add any additional offending characters into the field delimiters without editing your logic.
$: pat=$"[\"',_;:!##\$%)(* -]+"
$: echo "$pat"
["',_;:!##$%)(* -]+
$: cat file
"87687","institute 'Polytechnic, Brazil"
"342424","university; of-India, India"
"24343","univefrsity )columbia, Bogata, Colombia"
$: awk -F"$pat" '{printf "\"%s\",\"", $2; for(c=3;c<=NF;c++) printf "%s", tolower($c); print "\"" }' file
"87687","institutepolytechnicbrazil"
"342424","universityofindiaindia"
"24343","univefrsitycolumbiabogatacolombia"
(I hate the way that lone single quote throws the markup color/format parsing off, lol)

Answer 7

Another way using ruby. Edited the data to show only the second field is modified.
% ruby -r 'csv' -e 'f = open("file");
CSV.parse(f) do |i|
puts "\"" + i[0] + "\",\"" + i[1].downcase.gsub(/[ ,]/,"") + "\"" end'
"8768, 7","institutepolytechnicbrazil"
"342 424","universityofindiaindia"
"243 43","univefrsitycolumbiabogatacolombia"
Using FastCSV gives a huge speedup
gem install fastcsv
% ruby -r 'fastcsv' -e 'f = open("file");
FastCSV.raw_parse(f) do |i|
puts "\"" + i[0] + "\",\"" + i[1].downcase.gsub(/[ ,]/,"") + "\"" end'
"8768, 7","institutepolytechnicbrazil"
"342 424","universityofindiaindia"
"243 43","univefrsitycolumbiabogatacolombia"
Data
% cat file
"8768, 7","institute Polytechnic, Brazil"
"342 424","university of India, India"
"243 43","univefrsity columbia, Bogata, Colombia"

Answer 8

With your shown samples and attempts please try following GNU awk code using match function of it. Using regex (^"[^"]*",")([^"]*)(".*)$ in match function which will create 3 capturing groups and will store the value into arr and respectively I am fetching the values of it later in program to meet OP's requirement.
awk '
match($0,/(^"[^"]*",")([^"]*)(".*)$/,arr){
gsub(/[^[:alnum:]]+/,"",arr[2])
print arr[1] tolower(arr[2]) arr[3]
}
' Input_file

Answer 9

This might work for you (GNU sed):
sed -E s'/("[^"]*",)/\1\n/;h;s/.*\n//;s/[[:punct:] ]//g;s/.*/"\L&"/;H;g;s/\n.*\n//' file
Divide and rule.
Partition the line into two fields, make a copy, process the second field removing punctuation and spaces, re-quote and lowercase and then re-assemble the fields
An alternative, perhaps?
sed -E ':a;s/^("[^"]*",".*)[^[:alpha:]"](.*)/\L\1\2/;ta' file

Answer 10

Here is a way to do so in PHP.
Note: PHP will not output double quotes unless needed by the first column. The second column will never need double quotes, it has no space or special characters.
$max_line_length = 100;
if (($fp = fopen("file.csv", "r")) !== FALSE) {
while (($data = fgetcsv($fp, $max_line_length, ",")) !== FALSE) {
$data[1] = strtolower(preg_replace('/[\s[:punct:]]/', '', $data[1]));
fputcsv(STDOUT, $data, ',', '"');
}
fclose($fp);
}