Transforms keys of a map

R/dplyr_hof.R

hof_transform_keys

Description

Applies the transformation function specified to all keys of a map (this is essentially a dplyr wrapper to the transform_keys(expr, func) higher- order function, which is supported since Spark 3.0)

Usage

 
hof_transform_keys(x, func, expr = NULL, dest_col = NULL, ...) 

Arguments

Arguments Description
x The Spark data frame to be processed
func The transformation function to apply (it should take (key, value) as arguments and return a transformed key)
expr The map being transformed, could be any SQL expression evaluating to a map (default: the last column of the Spark data frame)
dest_col Column to store the transformed result (default: expr)
Additional params to dplyr::mutate

Examples

 
 
library(sparklyr) 
sc <- spark_connect(master = "local", version = "3.0.0") 
sdf <- sdf_len(sc, 1) %>% dplyr::mutate(m = map("a", 0L, "b", 2L, "c", -1L)) 
transformed_sdf <- sdf %>% hof_transform_keys(~ CONCAT(.x, " == ", .y))