GH-45619: [Python] Use f-string instead of string.format

[chilin0525]

Rationale for this change

See #45619.

What changes are included in this PR?

Refactor using f-string instead of string.format. But do not use f-string for following case, string.format allows passing parameters, making the code more reusable.

arrow/python/pyarrow/parquet/core.py

Lines 1624 to 1695 in 0fbf982

	_read_table_docstring = """
	{0}
	Parameters
	----------
	source : str, pyarrow.NativeFile, or file-like object
	If a string passed, can be a single file name or directory name. For
	file-like objects, only read a single file. Use pyarrow.BufferReader to
	read a file contained in a bytes or buffer-like object.
	columns : list
	If not None, only these columns will be read from the file. A column
	name may be a prefix of a nested field, e.g. 'a' will select 'a.b',
	'a.c', and 'a.d.e'. If empty, no columns will be read. Note
	that the table will still have the correct num_rows set despite having
	no columns.
	use_threads : bool, default True
	Perform multi-threaded column reads.
	schema : Schema, optional
	Optionally provide the Schema for the parquet dataset, in which case it
	will not be inferred from the source.
	{1}
	filesystem : FileSystem, default None
	If nothing passed, will be inferred based on path.
	Path will try to be found in the local on-disk filesystem otherwise
	it will be parsed as an URI to determine the filesystem.
	filters : pyarrow.compute.Expression or List[Tuple] or List[List[Tuple]], default None
	Rows which do not match the filter predicate will be removed from scanned
	data. Partition keys embedded in a nested directory structure will be
	exploited to avoid loading files at all if they contain no matching rows.
	Within-file level filtering and different partitioning schemes are supported.
	{3}
	use_legacy_dataset : bool, optional
	Deprecated and has no effect from PyArrow version 15.0.0.
	ignore_prefixes : list, optional
	Files matching any of these prefixes will be ignored by the
	discovery process.
	This is matched to the basename of a path.
	By default this is ['.', '_'].
	Note that discovery happens only if a directory is passed as source.
	pre_buffer : bool, default True
	Coalesce and issue file reads in parallel to improve performance on
	high-latency filesystems (e.g. S3). If True, Arrow will use a
	background I/O thread pool. If using a filesystem layer that itself
	performs readahead (e.g. fsspec's S3FS), disable readahead for best
	results.
	coerce_int96_timestamp_unit : str, default None
	Cast timestamps that are stored in INT96 format to a particular
	resolution (e.g. 'ms'). Setting to None is equivalent to 'ns'
	and therefore INT96 timestamps will be inferred as timestamps
	in nanoseconds.
	decryption_properties : FileDecryptionProperties or None
	File-level decryption properties.
	The decryption properties can be created using
	``CryptoFactory.file_decryption_properties()``.
	thrift_string_size_limit : int, default None
	If not None, override the maximum total string size allocated
	when decoding Thrift structures. The default limit should be
	sufficient for most Parquet files.
	thrift_container_size_limit : int, default None
	If not None, override the maximum total size of containers allocated
	when decoding Thrift structures. The default limit should be
	sufficient for most Parquet files.
	page_checksum_verification : bool, default False
	If True, verify the checksum for each page read from the file.
	Returns
	-------
	{2}
	{4}
	"""

Are these changes tested?

Via CI.

Are there any user-facing changes?

No.

• GitHub Issue: [Python] Use f-string instead of string.format #45619

[kou]

We have many string.format codes in https://github.com/apache/arrow/tree/main/python/pyarrow . If you want to work on this step by step (for example, 1 PR per file), could you open a sub-issue for each PR instead of associating all PRs to GH-45619? (GitHub added sub-issue related features recently.)

[chilin0525]

@kou Thank you for the reminder🙏. I personally prefer to implement all changes within a single PR, so I am converting the PR to draft status.

[chilin0525]

I have already changed all the files under the pyarrow folder. As discussed in #45619, certain scenarios where the template is reused across multiple methods using string.format will not be refactored to f-strings.

[raulcd]

Thanks for the PR, could you take a look on the CI failures:
https://github.com/apache/arrow/actions/runs/13620611692/job/38077510062?pr=45629#step:6:8540
There are some cases were the expected doctest is failing due to the changes.

[pitrou]

str is implicit in f-strings, you don't need to call it explicitly. Example:

>>> from decimal import Decimal
>>> d = Decimal('1.500')
>>> repr(d)
"Decimal('1.500')"
>>> str(d)
'1.500'
>>> f"d is {d}"
'd is 1.500'
>>> f"d is {d!r}"
"d is Decimal('1.500')"

[chilin0525]

Thanks for review! I will change this.

[chilin0525]

Solved in cef7a3b

[chilin0525]

Hi @kou @raulcd @pitrou , the PR #45679 found some files outside pyarrow using string.format. I just want to confirm whether I should update all occurrences of string.format across the entire project, rather than limiting the changes to files under pyarrow. Is that correct?

[pitrou]

I just want to confirm whether I should update all occurrences of string.format across the entire project, rather than limiting the changes to files under pyarrow. Is that correct?

You can, but you don't have to. It's as you prefer.

[chilin0525]

I just want to confirm whether I should update all occurrences of string.format across the entire project, rather than limiting the changes to files under pyarrow. Is that correct?

You can, but you don't have to. It's as you prefer.

Got it! I prefer to update all files in this PR, so I will mark it as a draft until all changes are made. Thanks!

[chilin0525]

@pitrou @kszucs Sorry for the late update. I’ve rechecked all the files and removed unnecessary f prefixes from f-strings. The CI error doesn’t appear to be related to this change — but please correct me if I’m wrong. Thanks!

[kou]

"C GLib & Ruby / AMD64 Windows MSVC GLib" will be fixed by #46006 .

[raulcd]

@chilin0525 will you have some time to rebase main and fix the conflicts?

[chilin0525]

@raulcd I've rebased onto main and resolved the conflicts. The CI error looks unrelated to this change. Let me know if there's anything else I should adjust. Thanks!

[raulcd]

@github-actions crossbow submit -g python

[raulcd]

I've applied some minor suggestions and fixed a new conflict with main. If CI is successful I am going to merge.

[github-actions]

Revision: 7079403

Submitted crossbow builds: ursacomputing/crossbow @ actions-11bf920665

Task	Status
example-python-minimal-build-fedora-conda
example-python-minimal-build-ubuntu-venv
test-conda-python-3.10
test-conda-python-3.10-hdfs-2.9.2
test-conda-python-3.10-hdfs-3.2.1
test-conda-python-3.10-pandas-latest-numpy-latest
test-conda-python-3.11
test-conda-python-3.11-dask-latest
test-conda-python-3.11-dask-upstream_devel
test-conda-python-3.11-hypothesis
test-conda-python-3.11-pandas-latest-numpy-1.26
test-conda-python-3.11-pandas-latest-numpy-latest
test-conda-python-3.11-pandas-nightly-numpy-nightly
test-conda-python-3.11-pandas-upstream_devel-numpy-nightly
test-conda-python-3.11-spark-master
test-conda-python-3.12
test-conda-python-3.12-cpython-debug
test-conda-python-3.13
test-conda-python-3.9
test-conda-python-3.9-pandas-1.1.3-numpy-1.19.5
test-conda-python-emscripten
test-cuda-python-ubuntu-22.04-cuda-11.7.1
test-debian-12-python-3-amd64
test-debian-12-python-3-i386
test-fedora-39-python-3
test-ubuntu-22.04-python-3
test-ubuntu-22.04-python-313-freethreading
test-ubuntu-24.04-python-3

[raulcd]

The CI failures are unrelated.
The minimal examples fail because the fork repository does not have the development tags. This is a known issue:

• [Python] Jobs fail if Pyarrow version is not correctly generated due to missing remote dev tags #44803

The Python 3.10 are related to the test_gdb.py issue:

• [CI][Python] Conda Python 3.10 jobs fail with UnicodeDecodeError due to gdb issue #46343

[conbench-apache-arrow]

After merging your PR, Conbench analyzed the 4 benchmarking runs that have been run so far on merge-commit 992bee2.

There were no benchmark performance regressions. 🎉

The full Conbench report has more details. It also includes information about 11 possible false positives for unstable benchmarks that are known to sometimes produce them.