Lua Script CSV file to table -

i'm pretty new lua, have troubles reading data csv file table. csv file consist of 4 columns. first column string other 3 double values. want is: open file, read in data , process data. testing want print data screen. later have open other file, robot programm, , pass data programm.

i execute script consol command lua script.lua. error message lua: script.lua:22: bad argument #1 ´format´ (number expected, got nil) stack traceback: [c]: in function ´string.format´ script.lua:22: in main chunk [c]: in?

can tell me i'm doing wrong?

edit: changed scritp little bit. new code

local open = io.open  local function read_file(path)     local file = open(path, "r") -- r read mode , b binary mode     --if not file return nil end     local coordinates = {}      line in io.lines(path)     local coordinate_name, coordinate_x, coordinate_y, coordinate_z = line:match("%s*(.-),%s*(.-),%s*(.-),%s*(.-)")     coordinates[#coordinates+1] = { coordinate_name=coordinate_name, coordinate_x = tonumber(coordinate_x), coordinate_y = tonumber(coordinate_y), coordinate_z = tonumber(coordinate_z) }     end      --file:close()     return coordinates end  local coordinates = read_file("data.csv")  _, coordinate in ipairs(coordinates)  -- use pairs or ipairs iterate on tables print(("x: %s, y: %s, z: %s"):format(coordinate.coordinate_x,                                      coordinate.coordinate_y,                                      coordinate.coordinate_z)) end  return 0; 

now can execute script, printed screen is: x: nil, y: nil, z: nil. far understand lua, nil means no values read table.

edit: file want read looks this:

after;-5;-5;0; after;-2;-5;0; after;5;-5;0; after;5;-2;0; after;5;5;0; after;2;5;0; after;-5;5;0; after;-5;2;0; after;-5;-5;0; intersects;5;-4;0 intersects;-5;-4;0 intersects;-5;-3;0 intersects;5;-3;0 intersects;5;-2;0 intersects;-5;-2;0 

edit: updated code:

local open = io.open  local function read_file(path)     local file = open(path, "r") -- r read mode , b binary mode     --if not file return nil end     local coordinates = {}      line in io.lines(path)      local coordinate_name,            coordinate_x,            coordinate_y,            coordinate_z = line:match("%s* (.*);%s*(.*);%s*(.*);%s*(.*);%s*(.*)")      coordinates[#coordinates+1] = { coordinate_name = coordinate_name, coordinate_x = tonumber(coordinate_x), coordinate_y = tonumber(coordinate_y), coordinate_z = tonumber(coordinate_z) }     print(("x: %s y: %4f z: %s"):format(coordinates.coordinate_x,                                      coordinates.coordinate_y,                                      coordinates.coordinate_z))     end      _, coordinate in ipairs(coordinates)         print(coordinates.coordinate_x, coordinates.coordinate_z, coordinates.coordinate_z)     end      file:close()      return coordinates end  local coordinates = read_file("data.csv")     _, coordinates in ipairs(coordinates)  -- use pairs or ipairs iterate on tables         print(("x: %s, y: %s, z: %s"):format(coordinates.coordinate_x,                                          coordinates.coordinate_y,                                          coordinates.coordinate_z))     end   return 0; 

i'm using lua 5.3.3 windows, script writen in luaedit , called line lua script.lua.

use (.*) in pattern instead of (.-). per docs, - match shortest pattern, seems bug out z coordinate in testing:

updated match file format posted

    local coordinate_name,           coordinate_x,           coordinate_y,           coordinate_z = line:match("([^;]*);([^;]*);([^;]*);([^;]*)") 

the tonumber handle space trimming , don't seem using coordinate_name anywhere. there plenty of string trim implementations can choose if need trim coordinate_name variable later on.

full script reference.

local open = io.open  local function read_file(path)     local file = open(path, "r") -- r read mode , b binary mode     --if not file return nil end     local coordinates = {}      line in io.lines(path)         local coordinate_name,         coordinate_x,         coordinate_y,         coordinate_z = line:match("([^;]*);([^;]*);([^;]*);([^;]*)")         coordinates[#coordinates+1] = { coordinate_name = coordinate_name, coordinate_x = tonumber(coordinate_x), coordinate_y = tonumber(coordinate_y), coordinate_z = tonumber(coordinate_z) }     end      file:close()      return coordinates end  local coordinates = read_file("data.csv") _, coordinate in ipairs(coordinates)  -- use pairs or ipairs iterate on tables     print(("x: %s, y: %s, z: %s"):format(coordinate.coordinate_x,     coordinate.coordinate_y,     coordinate.coordinate_z)) end  return 0;