Related codes

• polars.Config.set_tbl_cell_alignment() and polars.Config.set_tbl_cell_numeric_alignment() changes environment variables ("POLARS_FMT_TABLE_CELL_ALIGNMENT", "POLARS_FMT_TABLE_CELL_NUMERIC_ALIGNMENT")

  polars/py-polars/polars/config.py

  Lines 771 to 864 in 3d100a8

  	@classmethod
  	def set_tbl_cell_alignment(
  	cls, format: Literal["LEFT", "CENTER", "RIGHT"] | None
  	) -> type[Config]:
  	"""
  	Set table cell alignment.
  	Parameters
  	----------
  	format : str
  	* "LEFT": left aligned
  	* "CENTER": center aligned
  	* "RIGHT": right aligned
  	Examples
  	--------
  	>>> df = pl.DataFrame(
  	... {"column_abc": [1.0, 2.5, 5.0], "column_xyz": [True, False, True]}
  	... )
  	>>> pl.Config.set_tbl_cell_alignment("RIGHT") # doctest: +IGNORE_RESULT
  	>>> print(df)
  	shape: (3, 2)
  	┌────────────┬────────────┐
  	│ column_abc ┆ column_xyz │
  	│ --- ┆ --- │
  	│ f64 ┆ bool │
  	╞════════════╪════════════╡
  	│ 1.0 ┆ true │
  	│ 2.5 ┆ false │
  	│ 5.0 ┆ true │
  	└────────────┴────────────┘
  	Raises
  	------
  	ValueError: if alignment string not recognised.
  	"""
  	if format is None:
  	os.environ.pop("POLARS_FMT_TABLE_CELL_ALIGNMENT", None)
  	elif format not in {"LEFT", "CENTER", "RIGHT"}:
  	msg = f"invalid alignment: {format!r}"
  	raise ValueError(msg)
  	else:
  	os.environ["POLARS_FMT_TABLE_CELL_ALIGNMENT"] = format
  	return cls
  	@classmethod
  	def set_tbl_cell_numeric_alignment(
  	cls, format: Literal["LEFT", "CENTER", "RIGHT"] | None
  	) -> type[Config]:
  	"""
  	Set table cell alignment for numeric columns.
  	Parameters
  	----------
  	format : str
  	* "LEFT": left aligned
  	* "CENTER": center aligned
  	* "RIGHT": right aligned
  	Examples
  	--------
  	>>> from datetime import date
  	>>> df = pl.DataFrame(
  	... {
  	... "abc": [11, 2, 333],
  	... "mno": [date(2023, 10, 29), None, date(2001, 7, 5)],
  	... "xyz": [True, False, None],
  	... }
  	... )
  	>>> pl.Config.set_tbl_cell_numeric_alignment("RIGHT") # doctest: +IGNORE_RESULT
  	>>> print(df)
  	shape: (3, 3)
  	┌─────┬────────────┬───────┐
  	│ abc ┆ mno ┆ xyz │
  	│ --- ┆ --- ┆ --- │
  	│ i64 ┆ date ┆ bool │
  	╞═════╪════════════╪═══════╡
  	│ 11 ┆ 2023-10-29 ┆ true │
  	│ 2 ┆ null ┆ false │
  	│ 333 ┆ 2001-07-05 ┆ null │
  	└─────┴────────────┴───────┘
  	Raises
  	------
  	KeyError: if alignment string not recognised.
  	"""
  	if format is None:
  	os.environ.pop("POLARS_FMT_TABLE_CELL_NUMERIC_ALIGNMENT", None)
  	elif format not in {"LEFT", "CENTER", "RIGHT"}:
  	msg = f"invalid alignment: {format!r}"
  	raise ValueError(msg)
  	else:
  	os.environ["POLARS_FMT_TABLE_CELL_NUMERIC_ALIGNMENT"] = format
  	return cls

• display(pl.DataFrame()) calls NotebookFormatter.write_style() viaNotebookFormatter.write_render() and pl.DataFrame._repr_html_

  polars/py-polars/polars/dataframe/frame.py

  Lines 1263 to 1288 in 3d100a8

  	def _repr_html_(self, *, _from_series: bool = False) -> str:
  	"""
  	Format output data in HTML for display in Jupyter Notebooks.
  	Output rows and columns can be modified by setting the following ENVIRONMENT
  	variables:
  	* POLARS_FMT_MAX_COLS: set the number of columns
  	* POLARS_FMT_MAX_ROWS: set the number of rows
  	"""
  	max_cols = int(os.environ.get("POLARS_FMT_MAX_COLS", default=75))
  	if max_cols < 0:
  	max_cols = self.width
  	max_rows = int(os.environ.get("POLARS_FMT_MAX_ROWS", default=10))
  	if max_rows < 0:
  	max_rows = self.height
  	return "".join(
  	NotebookFormatter(
  	self,
  	max_cols=max_cols,
  	max_rows=max_rows,
  	from_series=_from_series,
  	).render()
  	)

• At the current version, NotebookFormatter.write_style() does not read the environment variables.

I think this is a good idea; in other areas¹ of the NotebookFormatter code we do read the related table environment variables, and I think should do the same here.

貢献を歓迎します :)

@alexander-beedie
Thank you for your acceptance! ご快諾いただきありがとうございます！

Just a draft, but I created PR #15830 to use "POLARS_FMT_TABLE_CELL_NUMERIC_ALIGNMENT" in NotebookFormatter.write_style() method and to update polars.Config.set_tbl_cell_alignment() docstring.

I'm trying the following unchecked tasks.

To-do

• NotebookFormatter.write_style() selects text-align reading "POLARS_FMT_TABLE_CELL_ALIGNMENT" env variable
• NotebookFormatter.write_style() selects text-align reading "POLARS_FMT_TABLE_CELL_NUMERIC_ALIGNMENT"
• update docs of polars.Config.set_tbl_cell_alignment()
• update docs of polars.Config.set_tbl_cell_numeric_alignment()
• add additional test for display (if possible, reading HTML directly?)

@alexander-beedie
I created #15915 for review.
Could you review it when you get some time?

I struggled to use pre-commit on my PC today, but could not install ruff check with errors.
I will try installation later or use my forked repository for repeated tests.

#15915 does not change any Rust codes, but coverage-rust check failed with the following error message.
Revision of the workflow may be required with another PR.

libunwind: stepWithCompactEncoding - invalid compact unwind encoding
error: test failed, to rerun pass `-p polars-sql --test statements`