ARROW-13714: [Doc][Cookbook] Sharing data between R and Python - R (#99)

* Initial file

* Add to bookdown file

* Add examples

* Add example of PyArrow functions

* Initial file

* Add to bookdown

* Add examples

* Add example of PyArrow functions

* Capitalisation

* Update dependencies

* Add pyarrow installation

* Consistent capitalisation

Makefile

@@ -40,6 +40,7 @@ ifdef arrow_r_version
 else
 	cd ./r && Rscript ./scripts/install_dependencies.R
 endif
+	pip install pyarrow
 
 
 r: rdeps

r/content/_bookdown.yml

@@ -12,5 +12,6 @@ rmd_files: [
   "specify_data_types_and_schemas.Rmd",
   "arrays.Rmd",
   "tables.Rmd",
+  "python.Rmd",
   "flight.Rmd"
 ]

r/content/python.Rmd

@@ -0,0 +1,43 @@
+# Using PyArrow from R
+
+## Introduction
+
+For more information on using setting up and installing PyArrow to use in R, see 
+[the "Apache Arrow in Python and R with reticulate" vignette](https://arrow.apache.org/docs/r/articles/python.html). 
+
+## Create an Arrow object using PyArrow in R
+
+You want to use PyArrow to create an Arrow object in an R session.
+
+```{r, pyarrow_object}
+library(reticulate)
+pa <- import("pyarrow")
+pyarrow_scalar <- pa$scalar(42)
+pyarrow_scalar
+```
+```{r, test_pyarrow_object, opts.label = "test"}
+test_that("pyarrow_object", {
+  expect_s3_class(pyarrow_scalar, "pyarrow.lib.Scalar")
+})
+```
+
+## Call a PyArrow function from R
+
+You want to call a PyArrow function from your R session.
+
+```{r, pyarrow_func}
+table_1 <- Table$create(mtcars[1:5,])
+table_2 <- Table$create(mtcars[11:15,])
+
+pa$concat_tables(tables = list(table_1, table_2)) %>%
+  collect()
+```
+```{r, test_pyarrow_func, opts.label="test"}
+test_that("pyarrow_func", {
+  expect_equal(
+    collect(pa$concat_tables(tables = list(table_1, table_2))),
+    collect(Table$create(mtcars[c(1:5,11:15),]))
+  )
+})
+```
+

r/scripts/install_dependencies.R

@@ -81,7 +81,8 @@ install_arrow_version <- function(version_to_install) {
   }
 }
 
-dependencies <- c("testthat", "bookdown", "knitr", "purrr", "remotes", "dplyr")
+dependencies <- c("testthat", "bookdown", "knitr", "purrr", "remotes", 
+                  "dplyr", "stringr", "reticulate")
 
 for (dependency in dependencies) {
   load_package(dependency)