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))
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 |