pull: Extract a single column

In hadley/dplyr: A Grammar of Data Manipulation

Extract a single column

Description

pull() is similar to $. It's mostly useful because it looks a little nicer in pipes, it also works with remote data frames, and it can optionally name the output.

Usage

pull(.data, var = -1, name = NULL, ...)

Arguments

.data	A data frame, data frame extension (e.g. a tibble), or a lazy data frame (e.g. from dbplyr or dtplyr). See Methods, below, for more details.
var	A variable specified as: a literal variable name a positive integer, giving the position counting from the left a negative integer, giving the position counting from the right. The default returns the last column (on the assumption that's the column you've created most recently). This argument is taken by expression and supports quasiquotation (you can unquote column names and column locations).
name	An optional parameter that specifies the column to be used as names for a named vector. Specified in a similar manner as var.
...	For use by methods.

Value

A vector the same size as .data.

Methods

This function is a generic, which means that packages can provide implementations (methods) for other classes. See the documentation of individual methods for extra arguments and differences in behaviour.

The following methods are currently available in loaded packages: \Sexpr[stage=render,results=rd]{dplyr:::methods_rd("pull")}.

Examples

mtcars %>% pull(-1)
mtcars %>% pull(1)
mtcars %>% pull(cyl)


# Also works for remote sources
df <- dbplyr::memdb_frame(x = 1:10, y = 10:1, .name = "pull-ex")
df %>%
  mutate(z = x * y) %>%
  pull()


# Pull a named vector
starwars %>% pull(height, name)

hadley/dplyr documentation built on Nov. 6, 2024, 4:48 p.m.