pull: Pull out a single variable

In olascodgreat/samife: A Grammar of Data Manipulation

Description

This works like [[ for local data frames, and automatically collects before indexing for remote data tables.

Usage

pull(.data, var = -1)

Arguments

.data	A table of data
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 positions).

Examples

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

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

olascodgreat/samife documentation built on May 13, 2019, 6:11 p.m.