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new 18f86efaee GH-46853: [Python][Docs] Document preserving leading zeros
in CSV (#50477)
18f86efaee is described below
commit 18f86efaeebe0ef892777b709cbd8a3e2cac6aa9
Author: Kalyanam Dewri <[email protected]>
AuthorDate: Wed Aug 19 10:04:27 2026 -0700
GH-46853: [Python][Docs] Document preserving leading zeros in CSV (#50477)
Summary:
- Document that quoted numeric CSV values are still subject to type
inference.
- Add a doctest-backed example showing how `ConvertOptions.column_types`
preserves leading zeros.
- AI assistance was used for issue triage and drafting this documentation
example.
Validation:
- `/tmp/arrow-doccheck-46853/bin/python -m pytest --doctest-glob="*.rst"
docs/source/python/csv.rst -q` — passed, `1 passed`
- `git diff --check HEAD~1 HEAD` — passed
* GitHub Issue: #46853
Authored-by: kalyanamdewri <[email protected]>
Signed-off-by: AlenkaF <[email protected]>
---
docs/source/python/csv.rst | 12 ++++++++++++
1 file changed, 12 insertions(+)
diff --git a/docs/source/python/csv.rst b/docs/source/python/csv.rst
index 28946d1599..0f61259dda 100644
--- a/docs/source/python/csv.rst
+++ b/docs/source/python/csv.rst
@@ -142,6 +142,18 @@ a :class:`ConvertOptions` instance and pass it to
:func:`read_csv`:
col1: [[1,2,3]]
col2: [["a","b","c"]]
+Quoted CSV values are still subject to type inference. To preserve formatting
+such as leading zeros, set the column type explicitly to ``string``:
+
+.. code-block:: python
+
+ >>> import io
+ >>> source = io.BytesIO(b'code\n"001"\n"002"\n')
+ >>> options = csv.ConvertOptions(column_types={'code': pa.string()})
+ >>> table = csv.read_csv(source, convert_options=options)
+ >>> table['code'].to_pylist()
+ ['001', '002']
+
.. note::
To assign a column as ``duration``, the CSV values must be numeric strings
that match the expected unit (e.g. ``60000`` for 60 seconds when
