Merge pull request #1699 from rstudio/compile-python

add `tools/compile-python.R` script

tools/compile-python.R

@@ -0,0 +1,19 @@
+#!/usr/bin/env Rscript
+
+package_dir <- Sys.getenv("R_PACKAGE_DIR", NA)
+if (is.na(package_dir))
+  package_dir <- path.package("reticulate")
+
+tryCatch({
+  owd <- setwd(package_dir)
+  for (stale_pycache in grep("__pycache__$", list.dirs(recursive = TRUE), value = TRUE))
+    unlink(stale_pycache, recursive = TRUE)
+
+  df <- reticulate::virtualenv_starter(all = TRUE)
+  df <- df[order(df$version, decreasing = TRUE), ]
+  df$minor <- df$version[, 1:2]
+  df <- df[!duplicated(df$minor), ]
+  for (python in df$path) {
+    reticulate:::system2t(python, "-m compileall config python")
+  }
+}, finally = setwd(owd))