Re: find position in a list made by string by searching incomplete
- To: mathgroup at smc.vnet.net
- Subject: [mg130363] Re: find position in a list made by string by searching incomplete
- From: Peter Pein <petsie at dordos.net>
- Date: Thu, 4 Apr 2013 22:33:16 -0400 (EDT)
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Am 04.04.2013 19:10, schrieb Joug Raw: > I have a list of strings like > list1={{"a", "b something", "a", "a", "b", "c", "b"} > In this list, 'something' is a sting that I will not know in advanced and > there are several spaces between the 'b' and the 'something' in one string. > The number of the spaces is unknown. > > I want to find out the position of the this "b something" sting in the > list. So, I did, > > Position[list1, "b*"] > > and I also tried, > Position[list1,"b"~~___ ] > > both of them gave me {} as results. > > Also Cases[list1,"b"~~___] or Cases[list1, "b*"] does not work. I can get > the correct position only if I give the exact "b something" as the > searching pattern. What is the easiest way to search with a incomplete > string pattern in this case? Thanks for your help. > > Hi Joug, first use StringPosition with a StringExpression as pattern. Then wrap a Position[] around that: list1={"a","b something","a","a","b","c","b","b sth. else"}; Position[StringPosition[list1, "b "~~__], Except[{}], 1, Heads->False] --> {{2},{8}} Peter