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
How are you calling get_datum? Show us the line where you call it that gives
you that error.
Sean O'Dell
···
On Monday 21 June 2004 11:08, Graham Nicholls wrote:
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'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
Where did you get 'datid'? Are you absolutely positive it's a String? I would suggest inspect()ing the variable in the debug statement. In fact, I would suggest doing several tests on the contents of the variable there, printing out datid.class, (datid =~ /\A\$\d\d\z/), etc...
and, (less importantly) I would remove some code there, just to make less code to check 
def get_datum(datid)
if $debug
puts "Getting data for id [#{datid.inspect}]" # inspect it
puts "class: #{datid.class}" # check the class
puts "valid? #{datid =~ /\A\$\d\d\z/}" # check via regexp matching
puts "@data.has_key? #{@data.has_key? datid}" # is there a key there?
end
@data.fetch(datid)
rescue IndexError => err
puts "No data for key [#{datid}] : #{err}"
@data.each {|k,v| puts "Key #{k} => #{v}"}
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.
There really should be absolutely no difference between using a variable and using a literal... I strongly suspect that somehow you are not getting the data your function expects.
Oh, and "Welcome!"
HTH,
Mark
···
On Jun 21, 2004, at 11:08 AM, Graham Nicholls wrote:
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