CODEWITHSUNDEEP
rlist
xtufer
xtufer

Reputation: 169

Turning two columns of data in R into a series of lists as long as the columns

I have two columns of data referring to international abbreviations for countries (their ISO 2-Code and ISO 3-Code). I am going to use this as a "dictionary" to substitute the 2Codes for the 3Codes in another table using the gsubfn() function. I had to create the dictionary list by entering manually as follows:

d_list<-list('ABW'='AW','AFG'='AF','AGO'='AO','AIA'='AI','ALA'='AX','ALB'='AL','AND'='AD',
          'ARE'='AE','ARG'='AR','ARM'='AM','ASM'='AS','ATG'='AG','AUS'='AU','AUT'='AT',
          'AZE'='AZ','BAH'='AZ','BDI'='BI','BEL'='BE','BEN'='BJ','BFA'='BF','BGD'='BD',
          'BGR'='BG','BHR'='BH','BIH'='BA','BLM'='BL','BLR'='BY','BLZ'='BZ','BMU'='BM',
          'BOL'='BO','BRA'='BR','BRB'='BB','BRN'='BN')

d_list is a list of 212 elements ... one element per "=".

Is there a way to create d_list from a table or multiple tables that have the 2Code and 3Code in columns? ... would make this process so much faster and less error prone.

Upvotes: 1

Views: 55

Answers (1)

thelatemail
thelatemail

Reputation: 93928

First, some test data:

df <- data.frame(code3 = c("ABW","AFG"), code2 = c("AW", "AF"))

If each of the 3-Code values have to be unique, then split it:

split(df$code2, df$code3)
#$ABW
#[1] "AW"
#
#$AFG
#[1] "AF"

If not, make a list and set the names manually:

as.list(setNames(df$code2, df$code3))
#$ABW
#[1] "AW"
#
#$AFG
#[1] "AF"

Upvotes: 1

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