How to detect identical part(s) inside string?

Posted by Horace Ho on Stack Overflow See other posts from Stack Overflow or by Horace Ho
Published on 2010-04-26T09:54:06Z Indexed on 2010/04/26 10:23 UTC
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Filed under:

regex

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ruby

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python

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pattern-matching

I try to break down the http://stackoverflow.com/questions/2711961/decoding-algorithm-wanted question into smaller questions. This is Part I.

Question:

two strings: s1 and s2
part of s1 is identical to part of s2
space is separator
how to extract the identical part(s)?

example 1:

s1 = "12 November 2010 - 1 visitor"
s2 = "6 July 2010 - 100 visitors"

the identical parts are "2010", "-", "1" and "visitor"

example 2:

s1 = "Welcome, John!"
s2 = "Welcome, Peter!"

the identical parts are "Welcome," and "!"

Python and Ruby preferred. Thanks

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