Visual LISP, AutoLISP and General Customization

Visual LISP, AutoLISP and General Customization

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Active Member
CAD-a-Mia
Posts: 10
Registered: ‎12-16-2010
Message 1 of 6 (214 Views)

Read second column from a CSV

214 Views, 5 Replies
10-18-2012 01:47 PM

If I have a CSV file (with no header) that contains three columns and I want to return values of  the second column as a list, how is the best method to do that?

 

I have seen something where one can separate a string into a list by a divider (in my case, the commas between the three columns) but the actual code for me to inspect was supposed to be in an attached ZIP file which I didn't see as part of the post.

 

An example of my CSV (as a list) wouild be:

 

("PO-30-10,PIN OAK,88-15" "PO-30-10,PIN OAK,88-01A" "JS-20-5,JUNIPER,63-04" "PP-40-10,POPLAR,38-22")

 

and I need the resulting list to be:

("PIN OAK" "PIN OAK" JUNIPER" "POPLAR")

 

Is there a LISP way to do this - or only VLISP?

 

                                      ~Mia

Mentor
southie
Posts: 291
Registered: ‎03-15-2007
Message 2 of 6 (198 Views)

Re: Read second column from a CSV

10-18-2012 06:08 PM in reply to: CAD-a-Mia

Mia

 

Here ia a way.

 

(setq xx '("PO-30-10,PIN OAK,88-15" "PO-30-10,PIN OAK,88-01A" "JS-20-5,JUNIPER,63-04" "PP-40-10,POPLAR,38-22"))

(foreach n xx

(setq a (vl-string-position (ascii ",") n))

(setq b (substr n (+ a 2)))

(setq c (vl-string-position (ascii ",") b))

(setq d (substr b 1 c))

(setq vv (append vv (list d)))

)

 

("PIN OAK" "PIN OAK" "JUNIPER" "POPLAR")

 

hth

*Expert Elite*
pbejse
Posts: 2,502
Registered: ‎11-24-2009
Message 3 of 6 (191 Views)

Re: Read second column from a CSV

10-18-2012 06:33 PM in reply to: CAD-a-Mia

HYG

 

(defun second (str / func str)
  (setq func (lambda (j) (substr j 1 (vl-string-position 44 j)))
        str (substr str (+ (strlen (func str)) 2))
	str (func str)
  )
)

 (mapcar 'second '("PO-30-10,PIN OAK,88-15" "PO-30-10,PIN OAK,88-01A" "JS-20-5,JUNIPER,63-04" "PP-40-10,POPLAR,38-22"))

 

Perhaps it would be better if you stripped the string right after the read-line 

(while (Setq x (read-line fl))
(setq lst (cons (second x) lst))
)

 

Do you really need a vanilla version of the code?

 

*Expert Elite*
pbejse
Posts: 2,502
Registered: ‎11-24-2009
Message 4 of 6 (178 Views)

Re: Read second column from a CSV

10-18-2012 09:46 PM in reply to: pbejse

A Generic code  (Vanilla)

 

(defun secondV (j n / x a b c i)
 (setq a "" b (lambda ()(substr j 2)) i 0)
        (while (and (wcmatch j "*`,*")
		    (setq x (ascii j))
		    (> n i))
	    (if (eq x 44)
	      	(setq c a a "" j (b) i (1+ i))
		(setq a (strcat a (chr x))
		      j (b))))
	       (if (> n i) j c ))

 

(Setq a "JS-20-5,JUNIPER,63-04")
(secondV a 1)
hth"JS-20-5"
(secondV a 2)
"JUNIPER"
(secondV a 3)
"63-04"

 

(setq lst '("PO-30-10,PIN OAK,88-15" "PO-30-10,PIN OAK,88-01A" "JS-20-5,JUNIPER,63-04" "PP-40-10,POPLAR,38-22"))

 

(mapcar '(lambda (r)(secondV r 1)) lst)

("PO-30-10" "PO-30-10" "JS-20-5" "PP-40-10")
(mapcar '(lambda (r)(secondV r 2)) lst)
("PIN OAK" "PIN OAK" "JUNIPER" "POPLAR")
(mapcar '(lambda (r)(secondV r 3)) lst)
("88-15" "88-01A" "63-04" "38-22")

 

HTH

 

 

 

Valued Mentor
martti.halminen
Posts: 344
Registered: ‎12-31-2009
Message 5 of 6 (169 Views)

Re: Read second column from a CSV

10-19-2012 02:28 AM in reply to: CAD-a-Mia

CAD-a-Mia wrote:

If I have a CSV file (with no header) that contains three columns and I want to return values of  the second column as a list, how is the best method to do that?

 


 

(defun csv-second-column (path separator)
  ;; produces a list of the items in the second column of a csv file. Separator as a single-character string.
  (mapcar '(lambda (line)
            (cadr (split-string line separator)))
          (file-to-list path)))


(defun split-string (str delim / pos)
  ;; Splits a string into a list of strings at every occurrence of the delim (single-letter string).
  (setq pos (vl-string-position (ascii delim) str))
  (if (null pos)
      (list str)
      (cons (substr str 1 pos)
            (split-string (substr str (+ pos 2)) delim))))

(defun file-to-list (filename / file result line)
  (if (findfile filename)
      (progn (setq file (open filename "r"))
             (while (setq line (read-line file))
               (setq result (cons line result)))
             (close file)
             (reverse result))
      (alert (strcat "File " filename " not found!"))))

 --

*Expert Elite*
pbejse
Posts: 2,502
Registered: ‎11-24-2009
Message 6 of 6 (163 Views)

Re: Read second column from a CSV

10-19-2012 02:59 AM in reply to: martti.halminen

FWIW: VL code for  delimiter separator

 

(defun _delFinder  (str md / d l str)
      (while (setq d (vl-string-position md str nil T))
            (setq l (cons (substr str (+ 2 d)) l)
                  str (substr str 1 d)))
      (cons str l)
      )

 

HTH

 

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