[Tutor] Regular expression grouping insert thingy

[Lang Hurst]

This is so trivial (or should be), but I can't figure it out.

I'm trying to do what in vim is

:s/\([0-9]\)x/\1*x/

That is, "find a number followed by an x and put a "*" in between the 
number and the x"

So, if the string is "6443x - 3", I'll get back "6443*x - 3"

I won't write down all the things I've tried, but suffice it to say, 
nothing has done it.  I just found myself figuring out how to call sed 
and realized that this should be a one-liner in python too.  Any ideas?  
I've read a lot of documentation, but I just can't figure it out.  Thanks.

-- 
There are no stupid questions, just stupid people.