keyholder is a package for storing information (keys) about rows of data frame like objects. The common use cases are to track rows of data without modifying it and to backup and restore information about rows. This is done with creating a class keyed_df which has special attribute “keys”. Keys are updated according to changes in rows of reference data frame.
keyholder is designed to work tightly with dplyr package. All its one- and two-table verbs update keys properly.
You can install keyholder from github with:
# install.packages("devtools")
devtools::install_github("echasnovski/keyholder")keyholder provides a set of functions to work with keys:
assign_keys() and key_by().keys(). Get one specific key with pull_key().restore_keys() and its scoped variants (*_all(), *_if() and *_at()).rename_keys() and its scoped variants.remove_keys() and its scoped variants. Completely unkey object with unkey().use_id() and special .id key.For more detailed explanations and examples see package vignettes and documentation.
library(dplyr)
library(keyholder)
mtcars_tbl <- mtcars %>% as_tibble()mtcars_tbl_id <- mtcars_tbl %>%
# Creates a key '.id' with row index
use_id() %>%
filter(vs == 1, gear == 4)
mtcars_tbl_id
#> # A keyed object. Keys: .id
#> # A tibble: 10 x 11
#> mpg cyl disp hp drat wt qsec vs am gear carb
#> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl>
#> 1 22.8 4 108.0 93 3.85 2.32 18.61 1 1 4 1
#> 2 24.4 4 146.7 62 3.69 3.19 20.00 1 0 4 2
#> 3 22.8 4 140.8 95 3.92 3.15 22.90 1 0 4 2
#> # ... with 7 more rows
mtcars_tbl_id %>% pull_key(.id)
#> [1] 3 8 9 10 11 18 19 20 26 32mtcars_tbl_keyed <- mtcars_tbl %>%
# Backup
key_by(vs, am, gear) %>%
# Modify
mutate(vs = am) %>%
group_by(vs) %>%
mutate(gear = max(gear))
# Restore with recomputing groups
mtcars_tbl_keyed %>%
restore_keys_all() %>%
all.equal(mtcars_tbl)
#> [1] TRUE
# Restore with renaming
mtcars_tbl_keyed %>%
restore_keys_at("vs", .funs = funs(paste0(., "_old")))
#> # A keyed object. Keys: vs, am, gear
#> # A tibble: 32 x 12
#> # Groups: vs [2]
#> mpg cyl disp hp drat wt qsec vs am gear carb vs_old
#> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl>
#> 1 21.0 6 160 110 3.90 2.620 16.46 1 1 5 4 0
#> 2 21.0 6 160 110 3.90 2.875 17.02 1 1 5 4 0
#> 3 22.8 4 108 93 3.85 2.320 18.61 1 1 5 1 1
#> # ... with 29 more rowsdplyr’s *_if scoped variants of verbs:# Restored key goes to the end of the tibble
mtcars_tbl %>%
key_by(mpg, .exclude = TRUE) %>%
mutate_if(is.numeric, round, digits = 0) %>%
restore_keys_all()
#> # A keyed object. Keys: mpg
#> # A tibble: 32 x 11
#> cyl disp hp drat wt qsec vs am gear carb mpg
#> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl>
#> 1 6 160 110 4 3 16 0 1 4 4 21.0
#> 2 6 160 110 4 3 17 0 1 4 4 21.0
#> 3 4 108 93 4 2 19 1 1 4 1 22.8
#> # ... with 29 more rows