feat!: make $rename()'s behavior closer to python polars'

NEWS.md

@@ -52,14 +52,17 @@
   `time_unit` (#1116).
 - The default value of the `rechunk` argument of `pl$concat()` is changed from
   `TRUE` to `FALSE` (#1125).
+- In `$rename()` for LazyFrame and DataFrame, key-value pairs of names are changed to
+  `old_name = "new_name"` instead of `new_name = "old_name"` (#1129).
+- In `$rename()` for LazyFrame and DataFrame, no argument is not allowed (#1129).
 - In all `$rolling_*()` functions, the arguments `center` and `ddof` must be
   named (#1115).
 
 ### New features
 
-- Experimental feature `$rename_with()` for LazyFrame and DataFrame.
+- Allow specify a function in `$rename()` for LazyFrame and DataFrame.
   They are equivalent to `polars.LazyFrame.rename(mapping: Callable[[str], str])`
-  or `polars.DataFrame.rename(mapping: Callable[[str], str])` in Python Polars (#1122).
+  or `polars.DataFrame.rename(mapping: Callable[[str], str])` in Python Polars (#1122, #1129).
 
 ## Polars R Package 0.16.4
 

R/dataframe__frame.R

@@ -1595,40 +1595,22 @@ DataFrame_pivot = function(
 #' Rename column names of a DataFrame
 #' @inherit pl_DataFrame return
 #' @inherit LazyFrame_rename params details
-#' @seealso
-#' - [`<DataFrame>$rename_with()`][DataFrame_rename_with]
 #' @examples
 #' df = pl$DataFrame(
 #'   foo = 1:3,
 #'   bar = 6:8,
 #'   ham = letters[1:3]
 #' )
 #'
-#' df$rename(apple = "foo")
-DataFrame_rename = function(...) {
-  self$lazy()$rename(...)$collect()
-}
-
-#' Rename column names of a DataFrame with a function
-#' @inherit pl_DataFrame return
-#' @inherit LazyFrame_rename_with description params details
-#' @seealso
-#' - [`<DataFrame>$rename()`][DataFrame_rename]
-#' @examples
-#' df = pl$DataFrame(
-#'   foo = 1:3,
-#'   bar = 6:8,
-#'   ham = letters[1:3]
-#' )
+#' df$rename(foo = "apple")
 #'
-#' df$rename_with(
+#' df$rename(
 #'   \(column_name) paste0("c", substr(column_name, 2, 100))
 #' )
-DataFrame_rename_with = function(fun) {
-  self$lazy()$rename_with(fun)$collect()
+DataFrame_rename = function(...) {
+  self$lazy()$rename(...)$collect()
 }
 
-
 #' @title Summary statistics for a DataFrame
 #'
 #' @description This returns the total number of rows, the number of missing

R/lazyframe__lazy.R

@@ -1540,66 +1540,48 @@ LazyFrame_melt = function(
 #' polars will block projection and predicate pushdowns at this node.
 #' @inherit pl_LazyFrame return
 #' @param ... One of the following:
-#'  - params like `new_name = "old_name"` to rename selected variables.
-#'  - as above but with params wrapped in a list
-#' @seealso
-#' - [`<LazyFrame>$rename_with()`][LazyFrame_rename_with]
+#' - Key value pairs that map from old name to new name, like `old_name = "new_name"`.
+#' - As above but with params wrapped in a list
+#' - An R function that takes the old names character vector as input and
+#'   returns the new names character vector.
 #' @examples
 #' lf = pl$LazyFrame(
 #'   foo = 1:3,
 #'   bar = 6:8,
 #'   ham = letters[1:3]
 #' )
 #'
-#' lf$rename(apple = "foo")$collect()
-LazyFrame_rename = function(...) {
-  mapping = list2(...)
-  if (length(mapping) == 0) {
-    return(self)
-  }
-  if (is.list(mapping[[1L]])) {
-    mapping = mapping[[1L]]
-  }
-  existing = unname(unlist(mapping))
-  new = names(mapping)
-  unwrap(.pr$LazyFrame$rename(self, existing, new), "in $rename():")
-}
-
-
-#' Rename column names of a LazyFrame with a function
+#' lf$rename(foo = "apple")$collect()
 #'
-#' This method is currently experimental and may
-#' change without it being considered a breaking change.
-#' @inherit LazyFrame_rename details return
-#' @param fun An R function that takes the old names character vector as input and
-#' returns the new names character vector.
-#' @seealso
-#' - [`<LazyFrame>$rename()`][LazyFrame_rename]
-#' @examples
-#' lf = pl$LazyFrame(
-#'   foo = 1:3,
-#'   bar = 6:8,
-#'   ham = letters[1:3]
-#' )
-#'
-#' lf$rename_with(
+#' lf$rename(
 #'   \(column_name) paste0("c", substr(column_name, 2, 100))
 #' )$collect()
-LazyFrame_rename_with = function(fun) {
-  uw = \(res) unwrap(res, "in $rename_with():")
-
-  {
-    existing = names(self)
-    new = fun(existing)
-  } |>
-    result() |>
-    uw()
+LazyFrame_rename = function(...) {
+  uw = \(res) unwrap(res, "in $rename():")
+
+  if (!nargs()) {
+    Err_plain("No arguments provided for `$rename()`.") |>
+      uw()
+  }
 
+  mapping = list2(...)
+  if (is.function(mapping[[1L]])) {
+    result({
+      existing = names(self)
+      new = mapping[[1L]](existing)
+    }) |>
+      uw()
+  } else {
+    if (is.list(mapping[[1L]])) {
+      mapping = mapping[[1L]]
+    }
+    new = unname(unlist(mapping))
+    existing = names(mapping)
+  }
   .pr$LazyFrame$rename(self, existing, new) |>
     uw()
 }
 
-
 #' Fetch `n` rows of a LazyFrame
 #'
 #' This is similar to `$collect()` but limit the number of rows to collect. It

tests/testthat/_snaps/after-wrappers.md

@@ -87,16 +87,15 @@
       [29] "lazy"             "limit"            "max"              "mean"            
       [33] "median"           "melt"             "min"              "n_chunks"        
       [37] "null_count"       "partition_by"     "pivot"            "print"           
-      [41] "quantile"         "rechunk"          "rename"           "rename_with"     
-      [45] "reverse"          "rolling"          "sample"           "schema"          
-      [49] "select"           "select_seq"       "shape"            "shift"           
-      [53] "shift_and_fill"   "slice"            "sort"             "sql"             
-      [57] "std"              "sum"              "tail"             "to_data_frame"   
-      [61] "to_list"          "to_raw_ipc"       "to_series"        "to_struct"       
-      [65] "transpose"        "unique"           "unnest"           "var"             
-      [69] "width"            "with_columns"     "with_columns_seq" "with_row_index"  
-      [73] "write_csv"        "write_ipc"        "write_json"       "write_ndjson"    
-      [77] "write_parquet"   
+      [41] "quantile"         "rechunk"          "rename"           "reverse"         
+      [45] "rolling"          "sample"           "schema"           "select"          
+      [49] "select_seq"       "shape"            "shift"            "shift_and_fill"  
+      [53] "slice"            "sort"             "sql"              "std"             
+      [57] "sum"              "tail"             "to_data_frame"    "to_list"         
+      [61] "to_raw_ipc"       "to_series"        "to_struct"        "transpose"       
+      [65] "unique"           "unnest"           "var"              "width"           
+      [69] "with_columns"     "with_columns_seq" "with_row_index"   "write_csv"       
+      [73] "write_ipc"        "write_json"       "write_ndjson"     "write_parquet"   
 
 ---
 
@@ -160,21 +159,21 @@
       [27] "median"                  "melt"                   
       [29] "min"                     "print"                  
       [31] "profile"                 "quantile"               
-      [33] "rename"                  "rename_with"            
-      [35] "reverse"                 "rolling"                
-      [37] "schema"                  "select"                 
-      [39] "select_seq"              "serialize"              
-      [41] "set_optimization_toggle" "shift"                  
-      [43] "shift_and_fill"          "sink_csv"               
-      [45] "sink_ipc"                "sink_ndjson"            
-      [47] "sink_parquet"            "slice"                  
-      [49] "sort"                    "sql"                    
-      [51] "std"                     "sum"                    
-      [53] "tail"                    "to_dot"                 
-      [55] "unique"                  "unnest"                 
-      [57] "var"                     "width"                  
-      [59] "with_columns"            "with_columns_seq"       
-      [61] "with_context"            "with_row_index"         
+      [33] "rename"                  "reverse"                
+      [35] "rolling"                 "schema"                 
+      [37] "select"                  "select_seq"             
+      [39] "serialize"               "set_optimization_toggle"
+      [41] "shift"                   "shift_and_fill"         
+      [43] "sink_csv"                "sink_ipc"               
+      [45] "sink_ndjson"             "sink_parquet"           
+      [47] "slice"                   "sort"                   
+      [49] "sql"                     "std"                    
+      [51] "sum"                     "tail"                   
+      [53] "to_dot"                  "unique"                 
+      [55] "unnest"                  "var"                    
+      [57] "width"                   "with_columns"           
+      [59] "with_columns_seq"        "with_context"           
+      [61] "with_row_index"         
 
 ---