cols: Create column specification

In readr: Read Rectangular Text Data

Create column specification

Description

cols() includes all columns in the input data, guessing the column types as the default. cols_only() includes only the columns you explicitly specify, skipping the rest. In general you can substitute list() for cols() without changing the behavior.

Usage

cols(..., .default = col_guess())

cols_only(...)

Arguments

...	Either column objects created by ⁠col_*()⁠, or their abbreviated character names (as described in the col_types argument of read_delim()). If you're only overriding a few columns, it's best to refer to columns by name. If not named, the column types must match the column names exactly.
.default	Any named columns not explicitly overridden in ... will be read with this column type.

Details

The available specifications are: (with string abbreviations in brackets)

• col_logical() [l], containing only T, F, TRUE or FALSE.

• col_integer() [i], integers.

• col_double() [d], doubles.

• col_character() [c], everything else.

• col_factor(levels, ordered) [f], a fixed set of values.

• col_date(format = "") [D]: with the locale's date_format.

• col_time(format = "") [t]: with the locale's time_format.

• col_datetime(format = "") [T]: ISO8601 date times

• col_number() [n], numbers containing the grouping_mark

• col_skip() [_, -], don't import this column.

• col_guess() [?], parse using the "best" type based on the input.

See Also

Other parsers: col_skip(), cols_condense(), parse_datetime(), parse_factor(), parse_guess(), parse_logical(), parse_number(), parse_vector()

Examples

cols(a = col_integer())
cols_only(a = col_integer())

# You can also use the standard abbreviations
cols(a = "i")
cols(a = "i", b = "d", c = "_")

# You can also use multiple sets of column definitions by combining
# them like so:

t1 <- cols(
  column_one = col_integer(),
  column_two = col_number()
)

t2 <- cols(
  column_three = col_character()
)

t3 <- t1
t3$cols <- c(t1$cols, t2$cols)
t3

readr documentation built on May 29, 2024, 2:37 a.m.