how to wright and read list

hello, here is what i got

if not fs.exists("/request.txt") then
    local file = io.open("/request.txt", "w")
    file:write("{ }")
    file:close()
end
if not fs.exists("/.submitted.txt") then
    local file = io.open("/.submitted.txt", "w")
    file:write("{ }")
    file:close()
end
local function getList()
local file = io.open("/request.txt", "r")
sNames = file:read()
file:close()
print(sNames)
requestList = textutils.unserialize(sNames)
print(requestList)
end
local function getSubmitted()
local file = io.open("/.submitted.txt", "r")
sSubmitted = file:read()
file:close()
tSubmitted = textutils.unserialize(sSubmitted)
end

local function addPlayer( sName )
getList()
getSubmitted()
table.insert(requestList, sName)
sNames = textutils.serialize(requestList)
local file = io.open("/request.txt", "w")
file:write(sNames)
file:close()
table.insert(tSubmitted, sName )
sSubmitted = textutils.serialize(tSubmitted)
local file = io.open("/.submitted.txt", "w")
file:write(sSubmitted)
file:close()
print ("Request Sent.")
sleep(1)
end
shell.run("clear")
print("Type Name")
sName = io.read()
addPlayer(sName)
shell.run("clear")
getList()

the code is from a program that i had someone make for me a while ago.
but when i do print(sNames) it comes out in this format

{[1]="25",[2]="10",[3]="26",}

and i want to know how to print it in this format

25,10,26

I'm unsure what the program is supposed to do, and what part is for what, but it looks like it's reading/writing from a plain text file.
I once printed a table's contents with
print([1])
print([2])
etc.
So why don't you see if that works? If it doesn't, please elaborate on what it's for so I know what I'm looking at. (and so will anyone else if I can't help you.)

i did

for i=1,num do
    write(requestList[i]..",")
end

and it worked

O…kay. Well, if I helped I'm glad, if not, still glad you got it working. Good luck with whatever it is that does.