Add methods to string objects.

[Negroup]

Hi all.
I'm writing a simple Python module containing functions to process
strings in various ways. Actually it works importing the module that
contains the function I'm interested in, and calling
my_module.my_function('mystring').

I was just asking if it is possible to "extend" string objects'
behaviour so that it becomes possible to invoke something like
'anystring'.my_method().

1) does the latter approach bring some advantages?
2) how is it possible to achieve this goal? 

Any pointer will be appreciated, thanks.