[R one-liners] #r #oneliner

rOneLiners.r

#-- capture folder path, filename, and extension from filepath
<filename> <- sub("(.*\\/)([^.]+)(\\.[[:alnum:]]+$)", "\\2", <path>)

#-- add leading zeros to number
sprintf("%02d", <num>) #2 here pads with zeros so that all characters hace 2 characters (e.g.9 > 09), 4 would make 39 > 0039
 
#-- timestamp for file etc.
format(now(), "%Y%m%d-%H%M%S")

#-- get unique string for row in dataframe
require(digest)
df$hash <- apply(df, 1, digest)

#-- read certain element from JSON list
sapply(list_object, "[[", "item_name")

#-- read tab-delimited data from Mac clipboard
d <- read.table(pipe("pbpaste"), sep="\t", header=TRUE)

#-- write dataframe to db table, overwrite or append as argument
dbWriteTable(con, DBI::Id(schema = "schema", table = "table",
d, row.names = F, overwrite = T)