How to extract text from a string using sed?
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My example string is as follows:

    This is 02G05 a test string 20-Jul-2012

Now from the above string I want to extract `02G05`. For that I tried the following regex with sed
 

    $ echo "This is 02G05 a test string 20-Jul-2012" | sed -n '/\d+G\d+/p'

But the above command prints nothing and the reason I believe is it is not able to match anything against the pattern I supplied to sed.

So, my question is what am I doing wrong here and how to correct it.

When I try the above string and pattern with python I get my result

    >>> re.findall(r'\d+G\d+',st)
    ['02G05']
    >>>