improve install warning message

Rmagic/DESCRIPTION

@@ -1,7 +1,7 @@
 Package: Rmagic
 Type: Package
 Title: MAGIC - Markov Affinity-Based Graph Imputation of Cells
-Version: 2.0.3
+Version: 2.0.3.999
 Authors@R: c(person(given = "David", family = "van Dijk", email = "davidvandijk@gmail.com", role = c("aut")),
 		         person(given = 'Scott', family = 'Gigante', email = 'scott.gigante@yale.edu', role = 'cre', 
 		                comment = c(ORCID = '0000-0002-4544-2764')))
@@ -22,5 +22,5 @@ Suggests:
     phateR
 License: GPL-2 | file LICENSE
 LazyData: true
-RoxygenNote: 6.1.1
+RoxygenNote: 7.0.2
 Encoding: UTF-8

Rmagic/NAMESPACE

@@ -8,6 +8,7 @@ S3method(magic,default)
 S3method(magic,seurat)
 S3method(print,magic)
 S3method(summary,magic)
+export(check_pymagic_version)
 export(install.magic)
 export(library.size.normalize)
 export(magic)

Rmagic/R/utils.R

@@ -9,7 +9,10 @@ null_equal <- function(x, y) {
   }
 }
 
+#' Check that the current MAGIC version in Python is up to date.
+#'
 #' @importFrom utils packageVersion
+#' @export
 check_pymagic_version <- function() {
   pyversion <- strsplit(pymagic$`__version__`, '\\.')[[1]]
   rversion <- strsplit(as.character(packageVersion("Rmagic")), '\\.')[[1]]
@@ -18,12 +21,12 @@ check_pymagic_version <- function() {
   if (as.integer(pyversion[1]) < major_version) {
     warning(paste0("Python MAGIC version ", pymagic$`__version__`, " is out of date (recommended: ",
                    major_version, ".", minor_version, "). Please update with pip ",
-                   "(e.g. pip install --upgrade magic-impute) or Rmagic::install.magic()."))
+                   "(e.g. ", reticulate::py_config()$python, " -m pip install --upgrade magic-impute) or Rmagic::install.magic()."))
     return(FALSE)
   } else if (as.integer(pyversion[2]) < minor_version) {
     warning(paste0("Python MAGIC version ", pymagic$`__version__`, " is out of date (recommended: ",
                    major_version, ".", minor_version, "). Consider updating with pip ",
-                   "(e.g. pip install --upgrade magic-impute) or Rmagic::install.magic()."))
+                   "(e.g. ", reticulate::py_config()$python, " -m pip install --upgrade magic-impute) or Rmagic::install.magic()."))
     return(FALSE)
   }
   return(TRUE)
@@ -113,7 +116,7 @@ install.magic <- function(envname = "r-reticulate", method = "auto",
   error = function(e) {
     stop(paste0(
       "Cannot locate MAGIC Python package, please install through pip ",
-      "(e.g. pip install magic-impute) and then restart R."
+      "(e.g. ", reticulate::py_config()$python, " -m pip install magic-impute) and then restart R."
     ))
   }
   )