read csv and print latex tabular

readcsv.lua

readcsv = readcsv or {}
local readcsv = readcsv

local function readcsvlines (s, sep)
  sep = sep or ','
  s   = s .. "\n"
  s   = s:gsub("[\r\n]+", "\n") -- unix newline
  local curr, t = 1, {{}}
  while true do
    local tt, i, a, c = t[#t], curr
    if s:find('^"', curr) then -- starts with doublequote
      repeat
        a, i, c = s:find('"(.)', i+1) -- "" or ", or "\n
      until c ~= '"'
      tt[#tt+1] = s:sub(curr+1, a-1):gsub('""', '"') -- restore double doublequotes
    else
      a, i, c = s:find("(["..sep.."\n])", curr)
      tt[#tt+1] = s:sub(curr, a-1)
    end
    curr = i + 1
    if curr > s:len() then break end
    if c == "\n" then t[#t+1] = {} end -- prepare another line
  end
  return t
end
-- http://www.lua.org/pil/20.4.html
-- https://tools.ietf.org/html/rfc4180#section-2

local function readcsvfile (f, sep)
  local fh = io.open(kpse.find_file(f), "r")
  local t = readcsvlines(fh:read("*all"), sep)
  fh:close()
  return t
end

local function parse_option (opt, s, length)
  s = s .. ","
  local curr = 1
  while true do
    local k, v, i
    _, i, k = s:find("%s*([^,]-)%s*=%s*", curr)
    if not i then break end
    curr = i + 1
    _, i, v = s:find("^(%b{})%s*,+", curr)
    if i then
      v = v:gsub("^{(.-)}$", "%1")
    else
      _, i, v = s:find("(.-)%s*,+", curr)
    end
    curr = i + 1
    if k and v and k ~= "" then
      local row = k:match("^afterrow(.+)")
      if row == "*" then
        for l=0, length do
          opt.afterrow[l] = v
        end
      elseif row then
        opt.afterrow[tonumber(row)] = v
      else
        opt[k] = v
      end
    end
  end
  return opt
end

local function select_cols (t, cols)
  if not cols or cols == "" then return t end
  cols = cols:explode(",+")
  for i, v in ipairs(cols) do
    cols[i] = tonumber(v)
  end
  local tt = {}
  for i, v in ipairs(t) do
    tt[i] = {}
    for _, c in ipairs(cols) do
      tt[i][#tt[i]+1] = t[i][c]
    end
  end
  return tt
end

local function skip_rows (rows)
  local t = {}
  if not rows or rows == "" then return t end
  rows = rows:explode(",+")
  for _, v in ipairs(rows) do
    t[tonumber(v)] = true
  end
  return t
end

local catreg = { string = -2, latex  = -1, }

local function csv2tabular(f, sep, op)
  local t = readcsvfile(f, sep)
  local opt = {
    header   = "\\begin{tabular}{"..string.rep("r", #t[1]).."}",
    footer   = "\\end{tabular}",
    afterrow = { [0] = "\\hline", [1] = "\\hline", [#t] ="\\hline" },
    catcode  = "string", -- string or latex
    crlf     = " ",
    newline  = "\\\\",
  }
  opt = parse_option(opt, op, #t)
  t   = select_cols(t, opt.columns)
  local skiprows = skip_rows(opt.skiprows)
  -- now print tablular
  tex.sprint(opt.header)
  if opt.afterrow[0] then tex.sprint(opt.afterrow[0]) end
  for i, v in ipairs(t) do
    if not skiprows[i] then
      for ii, vv in ipairs(v) do
        tex.tprint({catreg[opt.catcode], (vv:gsub("\n", opt.crlf))},
                   {ii < #v and "&" or opt.newline})
      end
      if opt.afterrow[i] then tex.sprint(opt.afterrow[i]) end
    end
  end
  tex.sprint(opt.footer)
end

readcsv.tabular = csv2tabular

readcsv.sty

\ProvidesPackage{readcsv}[2016/01/01 v0.0 CSV to tabular]

\directlua{require "readcsv"}

\protected\def\csvtabular{\def\csv@separator{,}\futurelet\next\csv@tabular}
\protected\def\tsvtabular{\def\csv@separator{\string\t}\futurelet\next\csv@tabular}

\def\csv@tabular{%
  \ifx[\next
    \expandafter\csv@@tabular
  \else
    \expandafter\csv@@tabular\expandafter[\expandafter]%
  \fi
}

\def\csv@@tabular[#1]#2{\directlua{%
  readcsv.tabular("#2", "\csv@separator", "\luaescapestring\expandafter{\detokenize{#1}}")
}}

\endinput
% csvtabular[options]{file}
% tsvtabular[options]{file}
%
%   option examples:
%
%       header=\begin{tabular}{rrr},
%       footer=\end{tabular},
%
%       columns={1,4,5},      select columns to print. default: all columns.
%
%       afterrow0=\hline,     tex code inserted before first line.
%       afterrow1=\hline,     tex code inserted after first line.
%       afterrow2=,           tex code inserted after second line.
%       afterrow*=\hline,     tex code inserted after each and every line.
%
%       newline=\\,           tabular new line.
%
%       crlf={ },             endline char in csv data will be converted to space.
%
%       catcode=string,       latex: allow tex commands. string: prints verbatim.

\documentclass{article}
\usepackage{readcsv}
\begin{document}
\begin{table}\centering\caption{CSV Table Test}
  \csvtabular[align=crrrr]{civil-gdp-pop.csv}
\end{table}
\end{document}