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str_split_csv

Splits strings into an array of strings using the given delimiter.

Available in version 6.1.0 and later.

Prototype

	function str_split_csv (
		string_val [*] : string, 
		delimiter [1] : string, 
		option [1] : integer 
	)
	return_val [*][*] : string

Arguments

The input strings to split.

The delimiter to separate the strings (usually a comma).

An option on how to treat double or single quotes. There are four options:

0 - ignores any delimiter inside quotes (single or double)

1 - ignores any delimiter inside single quotes

2 - ignores any delimiter inside double quotes

3 - all delimiters are treated as separators

Return value

A 2D array of strings, dimensioned # lines x # fields. The number of lines will be the same as the number of lines in the input array.

Description

Note: In NCL V6.2.0 a bug was fixed in which delimiters inside of quotes were not handled correctly.

This function splits strings based on a delimiter. If there are consecutive delimiters in a string, then a missing value is inserted. If you want consecutive delimiters ignored, then use str_split instead.

See Also

str_split, str_concat

Examples

Example 1

Split a string according to a single space:

 str = "NCL has many features common to modern programming languages, including types, variables, and more."
 strs = str_split_csv(str, ",", 0)
 print("'" + strs + "'")

Output will be:

(0,0) 'NCL has many features common to modern programming languages'
(0,1) ' including types'
(0,2) ' variables'
(0,3) ' and more.'

Example 2

Note that missing values are inserted between consecutive delimiters (in this case, comma). Also note that there are single quotes in the second string; opt=0 told the function to ignore the comma inside the quote. (The double quotes surrounding the actual strings are just NCL syntax characters for containg a string, so they are not "seen" by the parsing algorithm):

 str = (/"a0,a1,,,,a5,", \
 "c0,'c,1',,,c4,," /)
 opt = 0
 new_strs = str_split_csv(str, ",", opt)
 print(new_strs)

Output will be:

(0,0) a0
(0,1) a1
(0,2) missing
(0,3) missing
(0,4) missing
(0,5) a5
(0,6) missing
(1,0) c0
(1,1) 'c,1'
(1,2) missing
(1,3) missing
(1,4) c4
(1,5) missing
(1,6) missing

Example 3

In this example, opt=3 tells the function to treat the comma inside the quote as an actual delimiter:

 str = (/"a0,a1,,,,a5,", \
 "c0,'c,1',,,c4,," /)
 opt = 3
 new_strs = str_split_csv(str, ",", opt)
 print(new_strs)

Output will be:

(0,0) a0
(0,1) a1
(0,2) missing
(0,3) missing
(0,4) missing
(0,5) a5
(0,6) missing
(1,0) c0
(1,1) 'c
(1,2) 1'
(1,3) missing
(1,4) missing
(1,5) c4
(1,6) missing

Assume you have a CSV file (taken from a file on the budburst.org website) called "myfile.csv" with the following lines:

Obs ID,Obs Date,Species,Common Name,Phenophase ID,Phenophase Name,Obs Comment,Station ID,Station City,Station State,Station Zip,Elevation_m,Site Comment
11697,2011年02月19日,Tradescantia ohiensis,Spiderwort,3,First Flower,,4377,Rockledge,FL,32955,16,Not irrigated or fertilized directly
11701,2011年02月19日,Acer rubrum,Red maple,3,First Flower,,4460,Knoxville,TN,37919,,"large areas of lawn/field, but also many buildings, paved areas"
11702,2011年02月15日,Forsythia xintermedia,Forsythia,3,First Flower,"Prior ""observation"" of Feb 15, 2010 was a typo",4454,Knoxville,TN, ,,,
11715,2011年03月01日,,American Arborvitae,11,50% Color,This did not lose it's leaves during the winter.,4480,Bloomington,IN,,,,
14012,2011年11月07日,Rosa woodsii,Woods' rose,47,50% Color,,4752,Loveland,CO,80537,5200,"near beginning of trail, mixture of grassland and shrubland"

The following (very basic) script will read it in and print the various fields. This file contains a mix of double and single quotes, and commas inside the quotes, so you need to use opt=2:

 lines = asciiread("myfile.csv",-1,"string")
 split_lines = str_split_csv(lines,",",2)
 nlines = dimsizes(split_lines(:,0))
 nfields = dimsizes(split_lines(0,:))
 header = split_lines(0,:)
 do nl=1,nlines-1
 print("==================================================")
 do nf=0,nfields-1
 print(header(nf) + " : " + str_join(split_lines(nl,nf),", "))
 end do
 end do

The output will be:

 (0) ==================================================
 (0) Obs ID : 11697
 (0) Obs Date : 2011年02月19日
 (0) Species : Tradescantia ohiensis
 (0) Common Name : Spiderwort
 (0) Phenophase ID : 3
 (0) Phenophase Name : First Flower
 (0) Obs Comment : missing
 (0) Station ID : 4377
 (0) Station City : Rockledge
 (0) Station State : FL
 (0) Station Zip : 32955
 (0) Elevation_m : 16
 (0) Site Comment : Not irrigated or fertilized directly
 (0) ==================================================
 (0) Obs ID : 11701
 (0) Obs Date : 2011年02月19日
 (0) Species : Acer rubrum
 (0) Common Name : Red maple
 (0) Phenophase ID : 3
 (0) Phenophase Name : First Flower
 (0) Obs Comment : missing
 (0) Station ID : 4460
 (0) Station City : Knoxville
 (0) Station State : TN
 (0) Station Zip : 37919
 (0) Elevation_m : missing
 (0) Site Comment : "large areas of lawn/field, but also many buildings, paved areas"
 (0) ==================================================
 (0) Obs ID : 11702
 (0) Obs Date : 2011年02月15日
 (0) Species : Forsythia xintermedia
 (0) Common Name : Forsythia
 (0) Phenophase ID : 3
 (0) Phenophase Name : First Flower
 (0) Obs Comment : "Prior ""observation"" of Feb 15, 2010 was a typo"
 (0) Station ID : 4454
 (0) Station City : Knoxville
 (0) Station State : TN
 (0) Station Zip : 
 (0) Elevation_m : missing
 (0) Site Comment : missing
 (0) ==================================================
 (0) Obs ID : 11715
 (0) Obs Date : 2011年03月01日
 (0) Species : missing
 (0) Common Name : American Arborvitae
 (0) Phenophase ID : 11
 (0) Phenophase Name : 50% Color
 (0) Obs Comment : This did not lose it's leaves during the winter.
 (0) Station ID : 4480
 (0) Station City : Bloomington
 (0) Station State : IN
 (0) Station Zip : missing
 (0) Elevation_m : missing
 (0) Site Comment : missing
 (0) ==================================================
 (0) Obs ID : 14012
 (0) Obs Date : 2011年11月07日
 (0) Species : Rosa woodsii
 (0) Common Name : Woods' rose
 (0) Phenophase ID : 47
 (0) Phenophase Name : 50% Color
 (0) Obs Comment : missing
 (0) Station ID : 4752
 (0) Station City : Loveland
 (0) Station State : CO
 (0) Station Zip : 80537
 (0) Elevation_m : 5200
 (0) Site Comment : "near beginning of trail, mixture of grassland and shrubland"