refactor(python): Remove private DataFrame._read classmethods (#15521)

py-polars/Makefile

@@ -85,7 +85,7 @@ doctest: .venv build  ## Run doctests
 	$(VENV_BIN)/pytest tests/docs/test_user_guide.py -m docs
 
 .PHONY: docs
-docs: .venv build  ## Build Python docs (incremental)
+docs: .venv  ## Build Python docs (incremental)
 	@$(MAKE) -s -C docs html
 
 .PHONY: docs-clean

py-polars/polars/_utils/various.py

@@ -158,31 +158,6 @@ def range_to_slice(rng: range) -> slice:
     return slice(rng.start, rng.stop, rng.step)
 
 
-def handle_projection_columns(
-    columns: Sequence[str] | Sequence[int] | str | None,
-) -> tuple[list[int] | None, Sequence[str] | None]:
-    """Disambiguates between columns specified as integers vs. strings."""
-    projection: list[int] | None = None
-    new_columns: Sequence[str] | None = None
-    if columns is not None:
-        if isinstance(columns, str):
-            new_columns = [columns]
-        elif is_int_sequence(columns):
-            projection = list(columns)
-        elif not is_str_sequence(columns):
-            msg = "`columns` arg should contain a list of all integers or all strings values"
-            raise TypeError(msg)
-        else:
-            new_columns = columns
-        if columns and len(set(columns)) != len(columns):
-            msg = f"`columns` arg should only have unique values, got {columns!r}"
-            raise ValueError(msg)
-        if projection and len(set(projection)) != len(projection):
-            msg = f"`columns` arg should only have unique values, got {projection!r}"
-            raise ValueError(msg)
-    return projection, new_columns
-
-
 def _prepare_row_index_args(
     row_index_name: str | None = None,
     row_index_offset: int = 0,