Regular expressions

[Realware Systems]

Hi,

I have been looking at the docs at python.org but I must be missing 
something.

I cannot find an example of how to set up a regular expression.

I would like to know how to 

1. set up an RE
2. apply it to a string (to just perform a match)
3. apply it to a string to perform a replacement
4. how to join RE's

If any one can help I would much appreciate it 

Thanks in advance 
Derek

P.s the docs at python.org seem quite good as a reference but they do not 
provide examples of use (other than the tutorial and this is limited) 
does any one know of a site with good examples for a beginner. I have 
plenty of programing experience, in C/C++ some Perl + others but python 
is very new to me 

Thanks again