Escape from html %20

Question

I'm working on something in Python and I need to escape from %20, the space in a URL. For example:

"%20space%20in%20%d--" % ordnum

So I need to use %20 for a URL but then %d for a number. But I get this error:

TypeError: not enough arguments for format string

I know what the problem is I just don't know how to escape from a %20 and fix it.