Hi there:
I have a line, the format is like this
"num_of_item item1 item2...item_n" for example
"3 Tokyo Newyork Paris"
I want ruby parse this format, extract these keywords and save them in
an array.
I googled and search many forums, but can't find any matches.
Would anyone give me any ideas??
Thanks a lot!
--
Posted via http://www.ruby-forum.com/.
Hi there:
I have a line, the format is like this
"num_of_item item1 item2...item_n" for example"3 Tokyo Newyork Paris"
I want ruby parse this format, extract these keywords and save them in
an array.
I googled and search many forums, but can't find any matches.Would anyone give me any ideas??
If you just need to bust up the words via the spaces, this should probably work for you:
>> items = "3 Tokyo Newyork Paris".split[1..-1]
=> ["Tokyo", "Newyork", "Paris"]
James Edward Gray II
On Apr 26, 2009, at 3:48 PM, Martin Sharon wrote:
This is another opportunity to show Ruby's versatile style, e.g. functional
_, *items = "3 .a b c".split
R.
On Sun, Apr 26, 2009 at 10:56 PM, James Gray <james@grayproductions.net> wrote:
On Apr 26, 2009, at 3:48 PM, Martin Sharon wrote:
Hi there:
I have a line, the format is like this
"num_of_item item1 item2...item_n" for example"3 Tokyo Newyork Paris"
I want ruby parse this format, extract these keywords and save them in
an array.
I googled and search many forums, but can't find any matches.Would anyone give me any ideas??
If you just need to bust up the words via the spaces, this should probably
work for you:items = "3 Tokyo Newyork Paris".split[1..-1]
=> ["Tokyo", "Newyork", "Paris"]
I like...
(items = my_item_list).split.shift
Both you and I have examples, though, that do not return what the
statement using [1..-1] does. Mine, returns 3. Ah well, "items"
exists, though 
Todd
On Sun, Apr 26, 2009 at 4:11 PM, Robert Dober <robert.dober@gmail.com> wrote:
On Sun, Apr 26, 2009 at 10:56 PM, James Gray <james@grayproductions.net> wrote:
On Apr 26, 2009, at 3:48 PM, Martin Sharon wrote:
Hi there:
I have a line, the format is like this
"num_of_item item1 item2...item_n" for example"3 Tokyo Newyork Paris"
I want ruby parse this format, extract these keywords and save them in
an array.
I googled and search many forums, but can't find any matches.Would anyone give me any ideas??
If you just need to bust up the words via the spaces, this should probably
work for you:items = "3 Tokyo Newyork Paris".split[1..-1]
=> ["Tokyo", "Newyork", "Paris"]
This is another opportunity to show Ruby's versatile style, e.g. functional
_, *items = "3 .a b c".split
Oops...
(items = my_item_list.split).shift
Todd
On Sun, Apr 26, 2009 at 5:55 PM, Todd Benson <caduceass@gmail.com> wrote:
(items = my_item_list).split.shift
Thank you Todd, but the number of the keywords are dynamic.
and the array size is not fixed until program reads the first keywords
of the input line.
The line may be "3 tokyo newyork paris", also maybe
"6 toyota bmw honda GM Ford"
So I can't hard coded this array in the program.
How can I parse the line?
Thanks!
Todd Benson wrote:
On Sun, Apr 26, 2009 at 5:55 PM, Todd Benson <caduceass@gmail.com> > wrote:
(items = my_item_list).split.shift
Oops...
(items = my_item_list.split).shift
Todd
--
Posted via http://www.ruby-forum.com/\.
Martin Sharon wrote:
Thank you Todd, but the number of the keywords are dynamic.
and the array size is not fixed until program reads the first keywords
of the input line.
Explain why these solutions won't work for you:
strs = ["6 toyota bmw honda GM Ford", "3 tokyo newyork paris"]
strs.each do |str|
puts "1) split with subscripts:"
p str.split()[1..-1]
puts "2) split with parallel assignment:"
first, *therest = str.split()
p therest
puts
end
--output:--
1) split with subscripts:
["toyota", "bmw", "honda", "GM", "Ford"]
2) split with parallel assignment:
["toyota", "bmw", "honda", "GM", "Ford"]
1) split with subscripts:
["tokyo", "newyork", "paris"]
2) split with parallel assignment:
["tokyo", "newyork", "paris"]
--
Posted via http://www.ruby-forum.com/\.
Did you try our code? All of our solutions work for all examples you've posted so far…
James Edward Gray II
On Apr 26, 2009, at 7:25 PM, Martin Sharon wrote:
Thank you Todd, but the number of the keywords are dynamic.
and the array size is not fixed until program reads the first keywords
of the input line.
The line may be "3 tokyo newyork paris", also maybe
"6 toyota bmw honda GM Ford"So I can't hard coded this array in the program.
How can I parse the line?
If you look closely, you'll see that James' method grabs everything
from 1 to -1 (the end) of the array, omitting the zeroth element.
Robert's method assigns the garbage -- in this case, the whole array
-- to a dummy variable, and the important stuff to the var that you
care about (items).
My way was only slightly different. I opted to create the whole
array, and then drop the first without creating an extra object. I
had to use (items = my_item_list.split) inside parens like that
because #shift returns the object you popped off the front of the
list, and not the actual remaining stuff.
In all examples given, the size doesn't really matter... hah! Or as
they say, it depends
There are probably several ways to do this; I just like that particular one.
hth,
Todd
On Sun, Apr 26, 2009 at 7:25 PM, Martin Sharon <huangshuo.9@gmail.com> wrote:
Thank you Todd, but the number of the keywords are dynamic.
and the array size is not fixed until program reads the first keywords
of the input line.
The line may be "3 tokyo newyork paris", also maybe
"6 toyota bmw honda GM Ford"So I can't hard coded this array in the program.
How can I parse the line?
You know after looking at your original post, maybe you are trying to
create a digest, i.e. a Hash or associative array, with your keys as
the first "column".
In that case, you might try...
h = {}
f = my_string_list.each_line do |line|
key = (value = line.split).shift
h[key] = value
end
...or something like that.
Todd
On Sun, Apr 26, 2009 at 9:11 PM, Todd Benson <caduceass@gmail.com> wrote:
On Sun, Apr 26, 2009 at 7:25 PM, Martin Sharon <huangshuo.9@gmail.com> wrote:
Thank you Todd, but the number of the keywords are dynamic.
and the array size is not fixed until program reads the first keywords
of the input line.
The line may be "3 tokyo newyork paris", also maybe
"6 toyota bmw honda GM Ford"So I can't hard coded this array in the program.
How can I parse the line?If you look closely, you'll see that James' method grabs everything
from 1 to -1 (the end) of the array, omitting the zeroth element.Robert's method assigns the garbage -- in this case, the whole array
-- to a dummy variable, and the important stuff to the var that you
care about (items).My way was only slightly different. I opted to create the whole
array, and then drop the first without creating an extra object. I
had to use (items = my_item_list.split) inside parens like that
because #shift returns the object you popped off the front of the
list, and not the actual remaining stuff.In all examples given, the size doesn't really matter... hah! Or as
they say, it dependsThere are probably several ways to do this; I just like that particular one.
Oh my god.....
You and Jaem's codes really work!
Thanks a lot!
Todd Benson wrote:
My way was only slightly different. I opted to create the whole
array, and then drop the first without creating an extra object. I
had to use (items = my_item_list.split) inside parens like that
because #shift returns the object you popped off the front of the
list, and not the actual remaining stuff.In all examples given, the size doesn't really matter... hah! Or as
they say, it dependsThere are probably several ways to do this; I just like that particular
one.hth,
Todd
--
Posted via http://www.ruby-forum.com/\.
Todd Benson wrote:
My way was only slightly different. I opted to create the whole
array, and then drop the first without creating an extra object.
Note that you made ruby go through the laborious chore of shifting every
element in the array over one spot to the left.
--
Posted via http://www.ruby-forum.com/\.
That looks like I'm buoying my idea. I think any single one of these
methods will work just fine. I'm somewhat leaning towards [1..-1]
because it's very clear what's happening.
I'll stick with my #shift for now because it makes logical sense to
me. I'm not overly concerned in my work with speed or memory use.
James knows what he's talking about so really listen to him.
Todd
On Sun, Apr 26, 2009 at 9:11 PM, Todd Benson <caduceass@gmail.com> wrote:
If you look closely, you'll see that James' method grabs everything
from 1 to -1 (the end) of the array, omitting the zeroth element.Robert's method assigns the garbage -- in this case, the whole array
-- to a dummy variable, and the important stuff to the var that you
care about (items).My way was only slightly different. I opted to create the whole
array, and then drop the first without creating an extra object. I
had to use (items = my_item_list.split) inside parens like that
because #shift returns the object you popped off the front of the
list, and not the actual remaining stuff.In all examples given, the size doesn't really matter... hah! Or as
they say, it dependsThere are probably several ways to do this; I just like that particular one.
hth,
Todd
It's late and I'm golfing with myself. Apologies to the list for this
almost one-liner...
h = {}
s.each_line{|i|h[(v=i.split).shift]=v}
On Sun, Apr 26, 2009 at 9:47 PM, Todd Benson <caduceass@gmail.com> wrote:
In that case, you might try...
h = {}
f = my_string_list.each_line do |line|
key = (value = line.split).shift
h[key] = value
end...or something like that.
Is that really what happens? I thought it just reassigned a starting
point, and indexed from there. At least, that would make more sense
to me if it did.
Todd
On Sun, Apr 26, 2009 at 10:59 PM, 7stud -- <bbxx789_05ss@yahoo.com> wrote:
Todd Benson wrote:
My way was only slightly different. I opted to create the whole
array, and then drop the first without creating an extra object.Note that you made ruby go through the laborious chore of shifting every
element in the array over one spot to the left.
it works!
s.each instead of s.each_line
thanks!
Todd Benson wrote:
On Sun, Apr 26, 2009 at 9:47 PM, Todd Benson <caduceass@gmail.com> > wrote:
In that case, you might try...
h = {}
f = my_string_list.each_line do |line|
key = (value = line.split).shift
h[key] = value
end...or something like that.
It's late and I'm golfing with myself. Apologies to the list for this
almost one-liner...h = {}
s.each_line{|i|h[(v=i.split).shift]=v}
--
Posted via http://www.ruby-forum.com/\.
Let me rephrase. What is different on the underlying structure with
[1..-1] and #shift? I'm not sure if shift really moves everything,
but if it does, I wouldn't mind knowing.
Todd
On Sun, Apr 26, 2009 at 11:03 PM, Todd Benson <caduceass@gmail.com> wrote:
On Sun, Apr 26, 2009 at 10:59 PM, 7stud -- <bbxx789_05ss@yahoo.com> wrote:
Todd Benson wrote:
My way was only slightly different. I opted to create the whole
array, and then drop the first without creating an extra object.Note that you made ruby go through the laborious chore of shifting every
element in the array over one spot to the left.Is that really what happens? I thought it just reassigned a starting
point, and indexed from there. At least, that would make more sense
to me if it did.
Using 1.9.1. Sorry I didn't mention that. I haven't been following
the differences, but I seem to recall that was a change somewhere
along the line.
Todd
On Sun, Apr 26, 2009 at 10:32 PM, Martin Sharon <huangshuo.9@gmail.com> wrote:
it works!
s.each instead of s.each_line
If it shifts everything, it sure does it fast
p Time.now
arr = (1..100_000_000).to_a
p Time.now
arr.shift
p arr[0]
p Time.now
###output
Mon Apr 27 13:34:06 +0900 2009
Mon Apr 27 13:36:29 +0900 2009
2
Mon Apr 27 13:36:29 +0900 2009
Harry
On Mon, Apr 27, 2009 at 1:07 PM, Todd Benson <caduceass@gmail.com> wrote:
On Sun, Apr 26, 2009 at 11:03 PM, Todd Benson <caduceass@gmail.com> wrote:
On Sun, Apr 26, 2009 at 10:59 PM, 7stud -- <bbxx789_05ss@yahoo.com> wrote:
Todd Benson wrote:
My way was only slightly different. I opted to create the whole
array, and then drop the first without creating an extra object.Note that you made ruby go through the laborious chore of shifting every
element in the array over one spot to the left.Is that really what happens? I thought it just reassigned a starting
point, and indexed from there. At least, that would make more sense
to me if it did.Let me rephrase. What is different on the underlying structure with
[1..-1] and #shift? I'm not sure if shift really moves everything,
but if it does, I wouldn't mind knowing.Todd
--
A Look into Japanese Ruby List in English
Todd Benson wrote:
to me if it did.
Let me rephrase. What is different on the underlying structure with
[1..-1] and #shift? I'm not sure if shift really moves everything,
but if it does, I wouldn't mind knowing.Todd
shift changes the array in place:
1)
arr = [10, 20, 30]
y = arr.shift
puts y
p arr
--output:--
10
[20, 30]
subscripts create a new array:
2)
arr = [10, 20, 30]
p arr
print "id: ", arr.object_id
puts
x = arr[1..-1]
p x
print "id: ", x.object_id
puts
p arr
--output:--
[10, 20, 30]
id: 75950
[20, 30]
id: 75860
[10, 20, 30]
Is that really what happens? I thought it just reassigned a starting
point, and indexed from there. At least, that would make more sense
to me if it did.
Would it? What if you had an array that took up 3GB of memory and you
shifted off every element but the last one. Would you expect your array
to still occupy 3GB of memory?
On Sun, Apr 26, 2009 at 11:03 PM, Todd Benson <caduceass@gmail.com> > wrote:
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