Changed drop method to ignore missing columns - #61

CHANGELOG.md

@@ -7,6 +7,7 @@
 - Added `data_page_size` option to `write_parquet` method
 - Added `truncate_ragged_lines` option to `read_csv`, `read_csv_batched`, and `scan_csv` methods
 - Added precompiled gem for Linux x86-64 MUSL
+- Changed `drop` method to ignore missing columns
 
 ## 0.9.0 (2024-03-03)
 

lib/polars/data_frame.rb

@@ -2861,16 +2861,36 @@ def extend(other)
     #   # │ 2   ┆ 7.0 │
     #   # │ 3   ┆ 8.0 │
     #   # └─────┴─────┘
-    def drop(columns)
-      if columns.is_a?(::Array)
-        df = clone
-        columns.each do |n|
-          df._df.drop_in_place(n)
-        end
-        df
-      else
-        _from_rbdf(_df.drop(columns))
-      end
+    #
+    # @example Drop multiple columns by passing a list of column names.
+    #   df.drop(["bar", "ham"])
+    #   # =>
+    #   # shape: (3, 1)
+    #   # ┌─────┐
+    #   # │ foo │
+    #   # │ --- │
+    #   # │ i64 │
+    #   # ╞═════╡
+    #   # │ 1   │
+    #   # │ 2   │
+    #   # │ 3   │
+    #   # └─────┘
+    #
+    # @example Use positional arguments to drop multiple columns.
+    #   df.drop("foo", "ham")
+    #   # =>
+    #   # shape: (3, 1)
+    #   # ┌─────┐
+    #   # │ bar │
+    #   # │ --- │
+    #   # │ f64 │
+    #   # ╞═════╡
+    #   # │ 6.0 │
+    #   # │ 7.0 │
+    #   # │ 8.0 │
+    #   # └─────┘
+    def drop(*columns)
+      lazy.drop(*columns).collect(_eager: true)
     end
 
     # Drop in place.

lib/polars/lazy_frame.rb

@@ -2001,11 +2001,9 @@ def with_column(column)
     #   - List of column names.
     #
     # @return [LazyFrame]
-    def drop(columns)
-      if columns.is_a?(::String)
-        columns = [columns]
-      end
-      _from_rbldf(_ldf.drop(columns))
+    def drop(*columns)
+      drop_cols = Utils._expand_selectors(self, *columns)
+      self._from_rbldf(_ldf.drop(drop_cols))
     end
 
     # Rename column names.

lib/polars/utils.rb

@@ -364,5 +364,25 @@ def self._check_arg_is_1byte(arg_name, arg, can_be_empty = false)
         end
       end
     end
+
+    def self._expand_selectors(frame, *items)
+      items_iter = _parse_inputs_as_iterable(items)
+
+      expanded = []
+      items_iter.each do |item|
+        if is_selector(item)
+          selector_cols = expand_selector(frame, item)
+          expanded.concat(selector_cols)
+        else
+          expanded << item
+        end
+      end
+      expanded
+    end
+
+    # TODO
+    def self.is_selector(obj)
+      false
+    end
   end
 end