add_filename {arrow} | R Documentation |
Add the data filename as a column
Description
This function only exists inside arrow
dplyr
queries, and it only is
valid when querying on a FileSystemDataset
.
Usage
add_filename()
Details
To use filenames generated by this function in subsequent pipeline steps, you
must either call compute()
or
collect()
first. See Examples.
Value
A FieldRef
Expression
that refers to the filename
augmented column.
Examples
## Not run:
open_dataset("nyc-taxi") %>% mutate(
file =
add_filename()
)
# To use a verb like mutate() with add_filename() we need to first call
# compute()
open_dataset("nyc-taxi") %>%
mutate(file = add_filename()) %>%
compute() %>%
mutate(filename_length = nchar(file))
## End(Not run)
[Package arrow version 19.0.1.1 Index]