text = "sometext" <-- our string
text = text:sub(1,-2)
print(text) <-- gives "sometex"

对于❤✱♔“这样我就这样做了

function deleteLastCharacter(str)
return(str:gsub("[%z\1-\127\194-\244][\128-\191]*$",""))
end

for _,str in pairs{"❤✱♔" }do
print( deleteLastCharacter(str))
end