Fast CSV reader in Julia

gistfile1.txt

  foo2(filename, parsers; headers=true, delimiter=",", nrows=0) = open(filename) do f
   if headers 
     hdr = split(readline(f), delimiter)
   end
   lines = nrows == 0 ? [] : Vector(undef, nrows)
   r = 0
   while !eof(f)
     line = readline(f)
     row = map(x -> x[1](x[2]), zip(parsers, split(line, delimiter)))
     r += 1
     nrows == 0 ? push!(lines, row) : lines[r] = row
   end
   c = length(hdr)
   n = length(lines)
   if !headers
     hdr = ["_$i" for i in 1:c]
   end
   DataFrame([[L[j] for L in lines] for j in 1:c], Symbol.(hdr))
  end

julia> @btime foo2("random1000_1000.csv", $parsers; nrows=1000);
  591.724 ms (3021860 allocations: 114.26 MiB)