writing a R hashtable in to a CSV file?

问题

what i am trying to implement is to write an R hashtable to a csv file excel ( column like formatted file- keys in first column and values in the second). please consider this example. (the hash table is created by hash package)

<hash> containing 5 key-value pair(s).
  1 : 4
  2 : NULL
  3 : NULL
  4 : 3 1
  5 : 1 4

when I simply use this

write.csv(hash, file = "hash.csv",row.names=FALSE)

it gives me this error

Error in as.data.frame.default(x[[i]], optional = TRUE) : 
  cannot coerce class "structure("hash", package = "hash")" to a data.frame

so i try to create a dataframe from each key and values and then bind them:

a<-as.data.frame(keys(hash))
b<-as.data.frame(values(hash))
Error in data.frame(`1` = "4", `2` = NULL, `3` = NULL, `4` = c("3", "1" : 
  arguments imply differing number of rows: 1, 0, 2

then to create a list and a vector :

a<-keys(hash)
b<-values(hash)
d<-cbind(a,b)
f<-as.data.frame(d)
  a    b
1 1    4
2 2 NULL
3 3 NULL
4 4 3, 1
5 5 1, 4

but then when I try to write it:

write.csv(f, file = "hash.csv",row.names=FALSE)
Error in .External2(C_writetable, x, file, nrow(x), p, rnames, sep, eol,  : 
  unimplemented type 'list' in 'EncodeElement'

so is there any other way to do that or any way to fix this error ? thank you in advance.

回答1:

this somehow help me. but it is not yet the answer of my question as I was looking for a better solution.

a<-keys(hash)
  b<-values(hash)
  d<-cbind(a,b)
  L<-as.data.frame(d)
  L.df <- data.frame(lapply(L, as.character), stringsAsFactors=FALSE)
  write.csv(f.df, file ="file.CSV",row.names=FALSE)
    csv file format
    # a b
    # 1 4
    # 2 NULL
    # 3 NULL
    # 4 c("3", "1")
    # 5 c("1", "4")

来源：https://stackoverflow.com/questions/30165162/writing-a-r-hashtable-in-to-a-csv-file

标签

csv

save

dataframe

hashtable