move to left version 2

library(data.table)
library(plyr)
library(dplyr)
library(magrittr)

dt = fread('No, A, B, C, D, E, F, G
1, 1, 3, 0, 0, 4, 2, 1
2, 1, 0, 0, 0, 2, 0, 3
3, 0, 1, 0, 3, 0, 0, 0
4, 1, 3, 2, 1, 0, 0, 0
5, 0, 6, 0, 0, 0, 0, 0
6, 0, 0, 0, 0, 2, 2, 1
')
old_names = names(dt)
dt %<>% setnames(paste0("V", 1:ncol(dt)))
txt = dt %>% mutate_(Vcobime = paste0("paste(", paste0("V", 1:ncol(dt),
  collapse = ","), ", sep = \",\")")) %>% .$Vcobime %>% {gsub("0", "", .)}
tmp = gsub(",$", "", gsub("([^,]+)(,+)", "\\1,", txt))
maxNumComma = nchar(txt) - nchar(gsub(",", "", txt))
numCommaEach = nchar(tmp) - nchar(gsub(",", "", tmp))
txt = sapply(maxNumComma - numCommaEach, function(x){
  if (x > 0)
    return(paste0(rep(",", x), 0, collapse=""))
  else
    return("")
}) %>% paste0(tmp, .)
dt = fread(paste(txt, collapse = "\n")) %>% setnames(old_names)