How to delete array element and add to previous element

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Hello,

I have an array that has elements that are arrays.

It looks like this(I'll call it array), it has:
[
[POS1, POS2a\, POS2b, POS3, POS4],          # this array is in position
array[0]
[POS2c\, POS2d\, POS2e],                    # this array is in position
array[1]
[POS2f\, POS2g\, POS2h],                    # this array is in position
array[2]
[POS1, POS2a\, POS2b, POS3, POS4]           # this array is in position
array[3]

]

Notice that Im trying to escape the commas with the backslash in the
array.  Is this the proper ways to escape commas in arrays?  The POS2's
are separated with commas(not to confuse them with the commas that
separate the array elements).

So, what Im trying to do is have arrays array[1] and array[2] added to
position array[0][1] and then have array[1] and array [2] deleted and
the have the next element from array moved downward in into the position
where array[1] and array[2] use to be.

So the final array should look like this:
[
[POS1, POS2a\, POS2b\, POS2c\, POS2d\, POS2f\, POS2g\, POS2h\, POS2e,
POS3, POS4],
[POS1, POS2a\, POS2b, POS3, POS4]
]

Does it make sense to store all of this information inside arrays or
would hashes be better?  Im shuffling this data around to have ir ready
to be placed inside of a database.  Is this the best setup for that?

This is the first time I've had to move arrays around like this and it
got me really confused.  Also, should I split the POS2a\, POS2b\, POS2c\
up into another array and have a three leveled array?

Could someone please write a preliminary loop for this type of operation
to get me on the right track or give advice on what I should be doing.

Thanks in advance.
-- 
Posted via http://www.ruby-forum.com/.

0
Reply desertfox1 (24) 7/27/2007 12:15:33 AM

Hi --

On Fri, 27 Jul 2007, Al Cholic wrote:

> Hello,
>
> I have an array that has elements that are arrays.
>
> It looks like this(I'll call it array), it has:
> [
> [POS1, POS2a\, POS2b, POS3, POS4],          # this array is in position
> array[0]
> [POS2c\, POS2d\, POS2e],                    # this array is in position
> array[1]
> [POS2f\, POS2g\, POS2h],                    # this array is in position
> array[2]
> [POS1, POS2a\, POS2b, POS3, POS4]           # this array is in position
> array[3]
>
> ]
>
> Notice that Im trying to escape the commas with the backslash in the
> array.  Is this the proper ways to escape commas in arrays?  The POS2's
> are separated with commas(not to confuse them with the commas that
> separate the array elements).

I'm afraid I don't know what you mean.  What exactly are you trying to
do with those commas?


David

-- 
* Books:
   RAILS ROUTING (new! http://www.awprofessional.com/title/0321509242)
   RUBY FOR RAILS (http://www.manning.com/black)
* Ruby/Rails training
     & consulting:  Ruby Power and Light, LLC (http://www.rubypal.com)

0
Reply dblack (1323) 7/27/2007 12:48:33 AM


unknown wrote:
> Hi --
> 
> On Fri, 27 Jul 2007, Al Cholic wrote:
> 
>> [POS2f\, POS2g\, POS2h],                    # this array is in position
>> array[2]
>> [POS1, POS2a\, POS2b, POS3, POS4]           # this array is in position
>> array[3]
>>
>> ]
>>
>> Notice that Im trying to escape the commas with the backslash in the
>> array.  Is this the proper ways to escape commas in arrays?  The POS2's
>> are separated with commas(not to confuse them with the commas that
>> separate the array elements).
> 
> I'm afraid I don't know what you mean.  What exactly are you trying to
> do with those commas?
> 
> 
> David

Dont worry about the commas.  they could just as well be spaces.  Its 
just he way Im reasing in a file, in the file they are just separated by 
commas.
-- 
Posted via http://www.ruby-forum.com/.

0
Reply desertfox1 (24) 7/27/2007 1:19:25 AM

On Jul 26, 2007, at 8:15 PM, Al Cholic wrote:

> I have an array that has elements that are arrays.
>
> It looks like this(I'll call it array), it has:
> [
> [POS1, POS2a\, POS2b, POS3, POS4],          # this array is in  
> position array[0]
> [POS2c\, POS2d\, POS2e],                    # this array is in  
> position array[1]
> [POS2f\, POS2g\, POS2h],                    # this array is in  
> position array[2]
> [POS1, POS2a\, POS2b, POS3, POS4]           # this array is in  
> position array[3]
> ]
>
> Notice that Im trying to escape the commas with the backslash in the
> array.  Is this the proper ways to escape commas in arrays?  The  
> POS2's
> are separated with commas(not to confuse them with the commas that
> separate the array elements).

If you are showing here is intended to be Ruby code, it is simply bad  
syntax. AFAIK, backslashes have no escape function outside of strings  
[*] and regular expressions. Also, as written, those POS thingies are  
going to be treated as identifiers naming references to constant  
objects. Is that what you intended? Then your sub-arrays should be  
written something like

    [POS1, [POS2a, POS2b], POS3, POS4]
    [nil, [POS2c, POS2d, POS2e], nil, nil]

and so forth.

On the hand, if what you are showing is intended to represent data  
stored as text in a file, I think you would be better off with a  
different data format. Look at YAML or CSV. There are libraries for  
handling those well-established formats.

Regards, Morton

[*] I'm lumping back-tick expressions with strings here.

0
Reply m_goldberg (507) 7/27/2007 1:33:02 AM

>     [POS1, [POS2a, POS2b], POS3, POS4]
>     [nil, [POS2c, POS2d, POS2e], nil, nil]
> 

Sorry about the syntax.  I was just trying to show the array, it was not 
intended to be ruby code.  What Im trying to do is read a text file and 
then make sense of the data in that text file and store that info in a 
database.  I have managed to sort out into the arrays but need to get 
the POS2c etc elements into the same array (im guessing thats the best 
way to do it).

For example here is code that im shuffling:

49  7  RP13,RP15,RP17,RP19,RP24,  12X2  33XD  Wireless, Independent, 5% 
235003410229  Toshiba  7024022000
    RP32,RP33
50  4  RP27,RP28,RP30,RP31  10XC4  3X567  Network, Isolated, 5% 
2353454310103  Philips  7024010300
51  31  R1,R2,R8,R30,R32,R33,R35,  0603,R10K,1%  0603  3%,1/12W 
S1345310KFJ2  Bonshui  7563010300
    R37,R39,R41,R42,R43,R49,
    R50,R51,R52,R58,R68,R69,
    R71,R72,R74,R85,R95,R117,
    R129,R130,R155,R156,R158,
    R160

What I've done is split the text up into lines stored all the lines in 
an array with text.strip.split("\n")  But as you can see the R71, R129, 
the elements in the third column continue on the next line.  I need a 
way to get them into one place.  Because those elements that are on the 
next line are a continuation of the third column element.

-- 
Posted via http://www.ruby-forum.com/.

0
Reply desertfox1 (24) 7/27/2007 1:56:34 AM

I reposting my last response since there is no edit on this forum.

Sorry about the syntax.  I was just trying to show the array, it was not
intended to be ruby code.  What Im trying to do is read a text file and
then make sense of the data in that text file and store that info in a
database.  I have managed to sort out into the arrays but need to get
the POS2c etc elements into the same array (im guessing thats the best
way to do it).

For example here is code that im shuffling:

49  7  RP13,RP15,RP17,RP19,RP24,  12X2  33XD  Wireless, Independent, 5%
       RP32,RP33
50  4  RP27,RP28,RP30,RP31  10XC4  3X567  Network, Isolated, 5%
51  31  R1,R2,R8,R30,R32,R33,R35,  0603,R10K,1%  0603  3%,1/12W
        R37,R39,R41,R42,R43,R49,
        R50,R51,R52,R58,R68,R69,
        R71,R72,R74,R85,R95,R117,
        R129,R130,R155,R156,R158,
        R160

What I've done is split the text up into lines stored all the lines in
an array with text.strip.split("\n")  But as you can see the R71, R129,
the elements in the third column continue on the next line.  I need a
way to get them into one place.  Because those elements that are on the
next line are a continuation of the third column element.  The elements 
on the line are separated by tabs.

-- 
Posted via http://www.ruby-forum.com/.

0
Reply desertfox1 (24) 7/27/2007 1:59:53 AM

On Jul 26, 2007, at 9:59 PM, Al Cholic wrote:
> I reposting my last response since there is no edit on this forum.
>
> Sorry about the syntax.  I was just trying to show the array, it  
> was not
> intended to be ruby code.  What Im trying to do is read a text file  
> and
> then make sense of the data in that text file and store that info in a
> database.  I have managed to sort out into the arrays but need to get
> the POS2c etc elements into the same array (im guessing thats the best
> way to do it).
>
> For example here is code that im shuffling:
>
> 49  7  RP13,RP15,RP17,RP19,RP24,  12X2  33XD  Wireless,  
> Independent, 5%
>        RP32,RP33
> 50  4  RP27,RP28,RP30,RP31  10XC4  3X567  Network, Isolated, 5%
> 51  31  R1,R2,R8,R30,R32,R33,R35,  0603,R10K,1%  0603  3%,1/12W
>         R37,R39,R41,R42,R43,R49,
>         R50,R51,R52,R58,R68,R69,
>         R71,R72,R74,R85,R95,R117,
>         R129,R130,R155,R156,R158,
>         R160
>
> What I've done is split the text up into lines stored all the lines in
> an array with text.strip.split("\n")  But as you can see the R71,  
> R129,
> the elements in the third column continue on the next line.  I need a
> way to get them into one place.  Because those elements that are on  
> the
> next line are a continuation of the third column element.  The  
> elements
> on the line are separated by tabs.

I'm guessing that "51\t31\tR1,R2,..." means that this is the 51st  
"thing" and there are 31 of the Rnn's in the third column.  The  
following lines begin "\t\tR37,R39,..." and "\t\tR50,R51,..."

In that case, this fragment might help jump-start you toward a solution:

text = gets  # or however you're getting the next line

data = text.split("\t")  # or .split("\t", 6) to limit to 6 parts
expected = data[1].to_i  # here's where you get 31
data[2] = data[2].split(',').compact  # the .compact removes a  
possible nil from a trailing ','
found = data[2].length
while found < expected
   moretext = gets
   break unless moretext =~ /\A\t\t/ # \A anchors to start, then 2 TABs
   more_elements = moretext.split("\t",4)[2].split(',').compact
   data[2].concat(more_elements)
   found += more_elements.length
end

unless found == expected
   raise "found #{found}, but expected #{expected} on number #{data[0]}"
end


Yes, it's rough (but so is your problem statment ;-) and you might do  
better checking for the trailing comma on the line as an added  
indication that there are more elements to come.

Good Luck,

-Rob

Rob Biedenharn		http://agileconsultingllc.com
Rob@AgileConsultingLLC.com



0
Reply Rob7461 (595) 7/27/2007 2:24:04 AM

On Jul 26, 2007, at 9:59 PM, Al Cholic wrote:

> I reposting my last response since there is no edit on this forum.
>
> Sorry about the syntax.  I was just trying to show the array, it  
> was not
> intended to be ruby code.  What Im trying to do is read a text file  
> and
> then make sense of the data in that text file and store that info in a
> database.  I have managed to sort out into the arrays but need to get
> the POS2c etc elements into the same array (im guessing thats the best
> way to do it).
>
> For example here is code that im shuffling:
>
> 49  7  RP13,RP15,RP17,RP19,RP24,  12X2  33XD  Wireless,  
> Independent, 5%
>        RP32,RP33
> 50  4  RP27,RP28,RP30,RP31  10XC4  3X567  Network, Isolated, 5%
> 51  31  R1,R2,R8,R30,R32,R33,R35,  0603,R10K,1%  0603  3%,1/12W
>         R37,R39,R41,R42,R43,R49,
>         R50,R51,R52,R58,R68,R69,
>         R71,R72,R74,R85,R95,R117,
>         R129,R130,R155,R156,R158,
>         R160

Now I understand. That's a rather nasty data file. How I would go  
about reformatting to something more rational would depend on what  
the field separators really are. I mean is

49  7  RP13,RP15,RP17,RP19,RP24,  12X2  33XD  Wireless, Independent, 5%

really

49\t7\tRP13,RP15,RP17,RP19,RP24,\t12X2\t33XD\tWireless, Independent, 5%

which I construe as 6 tab-delimited fields, or am I misreading it?  
Also, can any field other than the second one spill over onto  
following lines? And is the white space after the commas in what I  
think is last field significant? That is, does 'Wireless,  
Independent, 5%' need to be handled differently than  
'RP13,RP15,RP17,RP19,RP24,'?

Regards, Morton

0
Reply m_goldberg (507) 7/27/2007 3:44:31 AM

Morton Goldberg wrote:
> On Jul 26, 2007, at 9:59 PM, Al Cholic wrote:
> 
>>
>>         R129,R130,R155,R156,R158,
>>         R160
> 
> Now I understand. That's a rather nasty data file. How I would go
> about reformatting to something more rational would depend on what
> the field separators really are. I mean is
> 
> 49  7  RP13,RP15,RP17,RP19,RP24,  12X2  33XD  Wireless, Independent, 5%
> 
> really
> 
> 49\t7\tRP13,RP15,RP17,RP19,RP24,\t12X2\t33XD\tWireless, Independent, 5%
> 
> which I construe as 6 tab-delimited fields, or am I misreading it?
> Also, can any field other than the second one spill over onto
> following lines? And is the white space after the commas in what I
> think is last field significant? That is, does 'Wireless,
> Independent, 5%' need to be handled differently than
> 'RP13,RP15,RP17,RP19,RP24,'?
> 
> Regards, Morton

Only the third column with the R37,R39,R41,R42,R43,R49 can spill over to 
the next line.  Yes, the elements are separated by tabs like you said. 
I have managed to get the lines into an array by just using
inputed_text.strip.split("\n")
So now I have an array that contains each line as its elements.  But the 
problem is that I need to get the spilled over lines into a subarray of 
the right line.  I think this is the easiest way to organize the data. 
After i get the spilled over elements to the right location i can go a 
head and put the data into a database because I know which element in 
the array represents what.  I hope this helped in clarifying the issue.

Thanks for you help so far.
-- 
Posted via http://www.ruby-forum.com/.

0
Reply desertfox1 (24) 7/27/2007 6:12:08 AM

2007/7/27, Morton Goldberg <m_goldberg@ameritech.net>:
> If you are showing here is intended to be Ruby code, it is simply bad
> syntax. AFAIK, backslashes have no escape function outside of strings
> [*] and regular expressions.

There are also line continuations:

RKlemme@padrklemme1 ~
$ ruby -e 'puts 1
> + 2'
1

RKlemme@padrklemme1 ~
$ ruby -e 'puts 1\
+ 2'
3

Kind regards

robert

0
Reply shortcutter (5780) 7/27/2007 6:46:56 AM

On Jul 27, 2007, at 2:12 AM, Al Cholic wrote:

> Only the third column with the R37,R39,R41,R42,R43,R49 can spill  
> over to
> the next line.  Yes, the elements are separated by tabs like you said.
> I have managed to get the lines into an array by just using
> inputed_text.strip.split("\n")
> So now I have an array that contains each line as its elements.   
> But the
> problem is that I need to get the spilled over lines into a  
> subarray of
> the right line.  I think this is the easiest way to organize the data.
> After i get the spilled over elements to the right location i can go a
> head and put the data into a database because I know which element in
> the array represents what.  I hope this helped in clarifying the  
> issue.

The following code isn't a full solution to your problem, but I think  
it might suggest a strategy you can use.

<code>
raw_data = DATA.read
data = []
raw_data.each do |line|
    data << line.chomp.split(/\t/)
end
primary = nil
data.each_with_index do |row, i|
    if row[0].empty?
       primary[2] << row[2]
       data[i] = nil
    else
       primary = row
    end
end
data.compact!
p data

__END__
49	7	RP13,RP15,RP17,RP19,RP24,	12X2	33XD	Wireless, Independent, 5%
		RP32,RP33
50	4	RP27,RP28,RP30,RP31 	10XC4	3X567	Network, Isolated, 5%
51	31	R1,R2,R8,R30,R32,R33,R35,	0603,R10K,1%	0603	3%,1/12W
		R37,R39,R41,R42,R43,R49,
		R50,R51,R52,R58,R68,R69,
		R71,R72,R74,R85,R95,R117,
		R129,R130,R155,R156,R158,
		R160
</code>

<result>
[["49", "7", "RP13,RP15,RP17,RP19,RP24,RP32,RP33", "12X2", "33XD",  
"Wireless, Independent, 5%"],
["50", "4", "RP27,RP28,RP30,RP31 ", "10XC4", "3X567", "Network,  
Isolated, 5%"],
["51", "31",  
"R1,R2,R8,R30,R32,R33,R35,R37,R39,R41,R42,R43,R49,R50,R51,R52,R58,R68,R6 
9,R71,R72,R74,R85,R95,R117,R129,R130,R155,R156,R158,R160", "0603,R10K, 
1%", "0603", "3%,1/12W"]]
</result>

Regards, Morton



0
Reply m_goldberg (507) 7/27/2007 4:55:07 PM

On Jul 27, 2007, at 12:55 PM, Morton Goldberg wrote:

> The following code isn't a full solution to your problem, but I  
> think it might suggest a strategy you can use.
>
> <code>
> raw_data = DATA.read
> data = []
> raw_data.each do |line|
>    data << line.chomp.split(/\t/)
> end
> recd = nil
> data.each_with_index do |row, i|
>    if row[0].empty?
>       recd[2] << row[2]
>       data[i] = nil
>    else
>       recd = row
>    end
> end
> data.compact!
> p data
>
> __END__
> 49	7	RP13,RP15,RP17,RP19,RP24,	12X2	33XD	Wireless, Independent, 5%
> 		RP32,RP33
> 50	4	RP27,RP28,RP30,RP31 	10XC4	3X567	Network, Isolated, 5%
> 51	31	R1,R2,R8,R30,R32,R33,R35,	0603,R10K,1%	0603	3%,1/12W
> 		R37,R39,R41,R42,R43,R49,
> 		R50,R51,R52,R58,R68,R69,
> 		R71,R72,R74,R85,R95,R117,
> 		R129,R130,R155,R156,R158,
> 		R160
> </code>
>
> <result>
> [["49", "7", "RP13,RP15,RP17,RP19,RP24,RP32,RP33", "12X2", "33XD",  
> "Wireless, Independent, 5%"],
> ["50", "4", "RP27,RP28,RP30,RP31 ", "10XC4", "3X567", "Network,  
> Isolated, 5%"],
> ["51", "31",  
> "R1,R2,R8,R30,R32,R33,R35,R37,R39,R41,R42,R43,R49,R50,R51,R52,R58,R68, 
> R69,R71,R72,R74,R85,R95,R117,R129,R130,R155,R156,R158,R160",  
> "0603,R10K,1%", "0603", "3%,1/12W"]]
> </result>

The following does the job in one pass, rather than three:

<code>
raw_data = DATA.read
data = []
recd = nil
raw_data.each do |line|
    row = line.chomp.split("\t")
    if row[0].empty?
       recd[2] << row[2]
    else
       data << (recd = row)
    end
end
p data
</code>

Regards, Morton



0
Reply m_goldberg (507) 7/27/2007 11:22:53 PM

> <code>
> raw_data = DATA.read
> data = []
> recd = nil
> raw_data.each do |line|
>     row = line.chomp.split("\t")
>     if row[0].empty?
>        recd[2] << row[2]
>     else
>        data << (recd = row)
>     end
> end
> p data
> </code>
> 
> Regards, Morton

Hi Morton,

Thank you very much for putting effort into this.  I was able to get it 
working, but could you explain how it works.  Here is the way I 
implemented:

def get_component_info(bom)       #gettting the bom array (each 
element=line)
  data = []                       #setting up a temp variable
  recd = nil
  bom.each do |line|              #starting to loop though each line
    row = line.chomp.split("\t")  #created new array row by splitting 
with tab
    if row[0].empty?
      recd[2] << row[2]
    else
      data << (recd = row)
    end
  end
data
end

Questions:
at this line:
if row[0].empty?

Why are you checking the first element of the array?  Would this always 
return false because there are no empty lines in the raw text file.

at this line:
recd[2] << row[2]

Does recd now become a an array?  And you are storing the third element 
of row in the third position of recd?  Why?

at this line:
data << (recd = row)

Is this the way to read it: assign row value to recd and store it in 
data?



I hope you can clarify these points.  It would be big help in 
understanding ruby better for me.

Thank you,

Chris

-- 
Posted via http://www.ruby-forum.com/.

0
Reply desertfox1 (24) 7/28/2007 12:08:52 AM

On Jul 27, 2007, at 8:08 PM, Al Cholic wrote:

> def get_component_info(bom)       #getting the bom array (each  
> element=line)
>   data = []                       #setting up a temp variable
>   recd = nil
>   bom.each do |line|              #starting to loop though each line
>     row = line.chomp.split("\t")  #created new array row by  
> splitting with tab
>     if row[0].empty?
>       recd[2] << row[2]
>     else
>       data << (recd = row)
>     end
>   end
> data
> end
>
> Questions:
> at this line:
> if row[0].empty?
>
> Why are you checking the first element of the array?  Would this  
> always
> return false because there are no empty lines in the raw text file.

    row = line.chomp.split("\t")

transforms one line of bom from a tab delimited record into an array  
of fields. row[0] holds the contents of the first field. If that  
content is an empty string, code will assume the line being processed  
is a spill-over line. If it is not empty, code will assume the  
beginning of a new record.

> at this line:
> recd[2] << row[2]
>
> Does recd now become a an array?  And you are storing the third  
> element
> of row in the third position of recd?  Why?

At this point, code assumes row is a spill-over and that the third  
field, row[2], is where the spill-over data lives. This line of code  
appends the spill-over data to the third field, recd[2], of the  
current record. Here the << operator is a string append.

> at this line:
> data << (recd = row)
>
> Is this the way to read it: assign row value to recd and store it in
> data?

At this point, code assumes it has a new record. The code here is  
shorthand for

    recd = row
    data << recd

The first code line above provides a way to reference this record  
later, should there be spill-over lines following it. The second code  
line adds (appends) the new record to the array of records the method  
is building. Here the << operator is an array append.

> I hope you can clarify these points.  It would be big help in
> understanding ruby better for me.

I hope I have clarified things sufficiently, but if I haven't, feel  
free to ask more.

Regards, Morton



0
Reply m_goldberg (507) 7/28/2007 3:19:30 AM

Morton Goldberg wrote:
> On Jul 27, 2007, at 8:08 PM, Al Cholic wrote:
> 
>>       data << (recd = row)
>> always
>> return false because there are no empty lines in the raw text file.
> 
>     row = line.chomp.split("\t")
> 
> transforms one line of bom from a tab delimited record into an array
> of fields. row[0] holds the contents of the first field. If that
> content is an empty string, code will assume the line being processed
> is a spill-over line. If it is not empty, code will assume the
> beginning of a new record.

The only line that I have trouble understanding is this one:
if row[0].empty?

I try to logically think about it.  Lets say it hits a spill-over line 
and it has to process the string "C22,C23,C26,C27".  So it chomps it at 
divides it up by tabs, which there are none because the chomp removed 
them if there were any.  So, now row is a one element array.  At this 
point I think row[0]="C22,C23,C26,C27" and row[1]=nil, row[2]=nil. 
Where is my logic flawed?

Whats the difference between chomp and strip.  I've only been using 
strip.

Thanks again.
-- 
Posted via http://www.ruby-forum.com/.

0
Reply desertfox1 (24) 7/28/2007 3:39:41 AM

On Jul 27, 2007, at 11:39 PM, Al Cholic wrote:

> The only line that I have trouble understanding is this one:
> if row[0].empty?
>
> I try to logically think about it.

Programming is more of an experimental science than a deductive one.  
If you have a theory like this, convert it into a code snippet and  
evaluate it (in irb, for example -- although I would do it in  
TextMate, but not everybody has that). One of Ruby's strengths is,  
being an interpreted language, it is very easy to test theories.

> Lets say it hits a spill-over line
> and it has to process the string "C22,C23,C26,C27".  So it chomps  
> it at
> divides it up by tabs, which there are none because the chomp removed
> them if there were any.  So, now row is a one element array.  At this
> point I think row[0]="C22,C23,C26,C27" and row[1]=nil, row[2]=nil.
> Where is my logic flawed?

You are wrong in thinking chomp removes any of the tabs. It only  
removes trailing end-of-line characters. Try

    "\t\ta,b,c\n".chomp.split("\t')

in irb. You will see it produces ["", "", "a,b,c"]

I hope you won't mind if I give you a bit of advice. I think you have  
reached the point in your Ruby journey where you will greatly benefit  
from two resources:

1. Programming Ruby, The Pragmatic Programmers Guide, 2nd Edition  
(aka the pickaxe book) by Dave Thomas

2. The Ruby Way, 2nd Edition, by Hal Fulton

> Whats the difference between chomp and strip.  I've only been using
> strip.

I think you will find it very helpful to have the PDF version of the  
pickaxe book on your computer to consult while you are writing code.  
It can instantly answer questions like this. I have my copy open on- 
screen all the time while I'm coding.

Regards, Morton

0
Reply m_goldberg (507) 7/28/2007 12:08:31 PM

On Jul 27, 2007, at 11:39 PM, Al Cholic wrote:

> Whats the difference between chomp and strip.  I've only been using
> strip.

Oh, yes, there's always ri. I tend to forget about it because I rely  
on my pickaxe PDF.

~ mg: ri String#chomp
----------------------------------------------------------- String#chomp
      str.chomp(separator=$/)   => new_str
------------------------------------------------------------------------
      Returns a new +String+ with the given record separator removed  
from
      the end of _str_ (if present). If +$/+ has not been changed from
      the default Ruby record separator, then +chomp+ also removes
      carriage return characters (that is it will remove +\n+, +\r+, and
      +\r\n+).

         "hello".chomp            #=> "hello"
         "hello\n".chomp          #=> "hello"
         "hello\r\n".chomp        #=> "hello"
         "hello\n\r".chomp        #=> "hello\n"
         "hello\r".chomp          #=> "hello"
         "hello \n there".chomp   #=> "hello \n there"
         "hello".chomp("llo")     #=> "he"

~ mg: ri String#strip
----------------------------------------------------------- String#strip
      str.strip   => new_str
------------------------------------------------------------------------
      Returns a copy of _str_ with leading and trailing whitespace
      removed.

         "    hello    ".strip   #=> "hello"
         "\tgoodbye\r\n".strip   #=> "goodbye"

Regards, Morton



0
Reply m_goldberg (507) 7/28/2007 12:23:05 PM

Morton Goldberg wrote:
> On Jul 27, 2007, at 12:55 PM, Morton Goldberg wrote:
> 
> <code>
> raw_data = DATA.read
> data = []
> recd = nil
> raw_data.each do |line|
>     row = line.chomp.split("\t")
>     if row[0].empty?
>        recd[2] << row[2]
>     else
>        data << (recd = row)
>     end
> end
> p data
> </code>

Great lesson for a Ruby Newbie!  I had to
struggle with why

    recd[2] << row[2]

changed data, but once one understands,
it is an eye opener.  Page 41 of Programming
Ruby explains, and yells gotcha at me.  Your
code turns it into a tool.

In a more traditional (less ruby) form:

> raw_data = DATA.read
> data = []
  i = -1
> raw_data.each do |line|
>     row = line.chomp.split("\t")
      if not row[0].empty?  # new logical line
         i += 1
         data[i] = row
>     else                  # continuation
         data[i][2] << row[2]
>     end
> end
> p data

Thanks, again.
Ian
-- 
Posted via http://www.ruby-forum.com/.

0
Reply iw1junk (1195) 7/28/2007 2:28:21 PM

> I think you will find it very helpful to have the PDF version of the
> pickaxe book on your computer to consult while you are writing code.
> It can instantly answer questions like this. I have my copy open on-
> screen all the time while I'm coding.
> 
> Regards, Morton

Thank you Morton.  You've been a big help.  I got the books now.

-- 
Posted via http://www.ruby-forum.com/.

0
Reply desertfox1 (24) 7/28/2007 4:56:31 PM

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