Parse,inspect and extract data.table from fst file
An API for reading fst file as data.table.
parse_fst(path) slice_fst(ft, row_no) select_fst(ft, ...) filter_fst(ft, ...) summary_fst(ft)
path |
path to fst file |
ft |
An object of class fst_table, returned by |
row_no |
An integer vector (Positive) |
... |
The filter conditions |
summary_fst could provide some basic information about
the fst table.
parse_fst returns a fst_table class.
select_fst and filter_fst returns a data.table.
# write the file first
path = tempfile(fileext = ".fst")
fst::write_fst(iris,path)
# parse the file but not reading it
parse_fst(path) -> ft
ft
class(ft)
lapply(ft,class)
names(ft)
dim(ft)
summary_fst(ft)
# get the data by query
ft %>% slice_fst(1:3)
ft %>% slice_fst(c(1,3))
ft %>% select_fst(Sepal.Length)
ft %>% select_fst(Sepal.Length,Sepal.Width)
ft %>% select_fst("Sepal.Length")
ft %>% select_fst(1:3)
ft %>% select_fst(1,3)
ft %>% select_fst("Se")
# return a warning with message
ft %>% select_fst("nothing")
ft %>% select_fst("Se|Sp")
ft %>% select_fst(cols = names(iris)[2:3])
ft %>% filter_fst(Sepal.Width > 3)
ft %>% filter_fst(Sepal.Length > 6 , Species == "virginica")
ft %>% filter_fst(Sepal.Length > 6 & Species == "virginica" & Sepal.Width < 3)Please choose more modern alternatives, such as Google Chrome or Mozilla Firefox.