CSV Reading Options
csv_read_options(
use_threads = option_use_threads(),
block_size = 1048576L,
skip_rows = 0L,
column_names = character(0),
autogenerate_column_names = FALSE,
encoding = "UTF-8",
skip_rows_after_names = 0L
)
Whether to use the global CPU thread pool
Block size we request from the IO layer; also determines
the size of chunks when use_threads is TRUE
.
Number of lines to skip before reading data (default 0).
Character vector to supply column names. If length-0
(the default), the first non-skipped row will be parsed to generate column
names, unless autogenerate_column_names
is TRUE
.
Logical: generate column names instead of
using the first non-skipped row (the default)? If TRUE
, column names will
be "f0", "f1", ..., "fN".
The file encoding. (default "UTF-8"
)
Number of lines to skip after the column names (default 0).
This number can be larger than the number of rows in one block, and empty rows are counted.
The order of application is as follows:
- skip_rows
is applied (if non-zero);
- column names are read (unless column_names
is set);
- skip_rows_after_names
is applied (if non-zero).
tf <- tempfile()
on.exit(unlink(tf))
writeLines("my file has a non-data header\nx\n1\n2", tf)
read_csv_arrow(tf, read_options = csv_read_options(skip_rows = 1))
#> # A tibble: 2 × 1
#> x
#> <int>
#> 1 1
#> 2 2
open_csv_dataset(tf, read_options = csv_read_options(skip_rows = 1))
#> FileSystemDataset with 1 csv file
#> 1 columns
#> x: int64