Re: String to List
- To: mathgroup at smc.vnet.net
- Subject: [mg77018] Re: [mg76959] String to List
- From: Bob Hanlon <hanlonr at cox.net>
- Date: Thu, 31 May 2007 03:41:18 -0400 (EDT)
- Reply-to: hanlonr at cox.net
a = "{x,16,x,1T,x}";
b = StringSplit[Fold[StringDrop[#1, #2] &, a, {1, -1}], ","]
{x,16,x,1T,x}
Head /@ b
{String,String,String,String,String}
c = b /. x_?(NumericQ[ToExpression[#]] &) :> ToExpression[x]
{x,16,x,1T,x}
Head /@ c
{String,Integer,String,String,String}
Bob Hanlon
---- "King wrote:
> I have a string which in general looks something like
>
> a="{x,16,x,1T,x}"
>
> In other words it looks like a list with a mixture of characters and
> numbers and so on. I want to pick out the individual elements of this
> (using the commas as delimiters)
>
> Clearly a[[1]] etc doesn't mean anything
>
> I can do b=ToExpression[a] and I get a list so b[[1]] is x and
> b[[2]]=16 (that is the number sixteen but I can convert this back into =
> a
> string with ToString. The problem is b[[4]] which ToExpression turns
> into T as it thinks I mean 1 x T.
>
> So I would appreciate help with either
>
> i) converting my original string to a list as I would like
>
> Or
>
> Ii) stopping the evaluation of 1T into T so that I can get the string 1T
>
> (The only thought I had was to step through the original string
> character by character telling it to put the characters into different
> elements of a list each time I pass a comma, but this looked a bit
> cumbersome).
>
> Many thanks,
>
> Peter King
>