Template Filter - stringformat issue

[DieHardMan 300]

I tried Django template built-in filter "stringformat" to fixed string length to 3 for example assume I have variable name "data" contain "A1" I want to display this variable as "A1 " (1 blank space) so my code is

{{ data|stringformat:":<3s" }}  --> Result is None

so I tried another 6 examples

{{ data|stringformat:":<3" }}  --> Result is None

{{ data|stringformat:"{:<3}" }}  --> Result is None

{{ data|stringformat:":3" }}  --> Result is None

{{ data|stringformat:"{:3}" }} --> Result is None

{{ data|stringformat:":<3s" }} --> Result is None

{{ data|stringformat:"3s" }} --> Result is "A1" not "A1 "

I'm not sure what I'm missing, I cannot find answer online if anyone could help I would be appriciate.