From: Graham Nicholls <graham@...>
Date: 2004-06-22T03:08:18+09:00
Subject: newbie problem with a hash

I've got a file which I've read in and split to make a hash like this:


def initialize(fname)
  @data=Hash.new
  begin
  IO.foreach(fname) do |line|
    key,value=line.chomp.split(":")
    @data[key]=value
  end
end

This gives a hash keyed on the first field of the file, where : is the
separator.            (NB How do I handle : in the data - prompt to self!)

But when I try to get the value associated with that key by a fetch, I get
and IndexError:

def get_datum(datid) # Typical datid is $01 - I've stripped off the colon.
 if $debug
   print("Getting data for id [#{datid}]\n") # Prints $01
 end

 begin
  #@data.fetch("$01") - this works OK,
  @data.fetch(datid)    # This causes an IndexError
  rescue IndexError => err
    print("No data for key [#{datid}] : #{err}\n")
    @data.each do |key,val| 
            printf("Key [%s] => [%s]\n",key,val) # Shows $01 => avalue (amongst
others)
    end
    exit(NO_DATA)
 end
end

I'm racking my brains, but to no avail.  If I put the key in as a literal,
it returns, but using the datid variable, I get an IndexError.

I'd appreciate a pointer - its probably something daft - it usually is, but
I haven't got a cardboard analyst.

PS I rather like Ruby - its more elegant than Python (but don't tell anyone
in c.l.python!), IMNSHO.
Graham
-- 
#include wit