Question

I have a csv file which has a few areas where / proceeded by nothing and proceeded by nothing that I’d like to strip out. The catch is, I also have other items in the file which have a / that I don’t want to strip out.

an example:

/abc, /, akaksdhfaiwe
/, /foo, /bar

I’d like to be:

/abc,, akaksdhfaiwe
, /foo, /bar

How do I do this? I can’t use gsub(‘^/’, ”) because it would strip out the /abc /foo /bar. And for the life of me, I can’t seem to find an ‘ends with’. I was hoping that \Z would work, no luck.

Any takers?

I’ve been using fasterCSV for a lot of the manipulation which has been pretty great so far.

Answer 1

If your file isn’t that big then you could slurp it into memory while cleaning it up and then write it out again:

clean = [ ]
CSV.open(your_csv).each { |r| csv << r.map { |e| e.sub(/^\s*\/$/, '') } }
out = CSV.open(your_csv, 'wb')
clean.each { |r| out << r }  
out.close

If you somehow have an incredibly massive CSV file that won’t fit in memory all at once:

out = CSV.open('tempfile.csv', 'wb')
CSV.open(your_csv).each { |r| out << r.map { |e| e.sub(/^\s*\/$/, '') } }
out.close
File.rename('tempfile.csv', your_csv)

Either should turn this:

/abc, /, akaksdhfaiwe
/, /foo, /bar

into

/abc,"", akaksdhfaiwe
"", /foo, /bar