str(int_var) formatted

[Tracubik]

Hi all,
i've to convert integer x to string, but if x < 10, the string have to be 
'0x' instead of simple 'x'

for example:

x = 9
str(x) --> '09'

x = 32
str(x) --> '32'

x represent hour/minute/second.

I can easily add '0' with a if then block, but is there a built-in way to 
add the '0' automatically?

Thanks
Nico