[Python] pyarrow schema.empty_table() does not preserve nullability of fields

[asfimport]

Introduced by PR: #2589

 

When a field in a schema is marked as not-nullable, calling empty_table() on the schema returns a table with nullable fields.

 

reproduction

>>> import pyarrow as pa
>>> s = pa.schema([pa.field('a', pa.int64(), nullable=False), pa.field('b', pa.int64())])

>>> s

a: int64 not null
b: int64

>>> e = s.empty_table()
>>> e

pyarrow.Table
a: int64
b: int64

>>> e.schema

a: int64
b: int64

>>> assert s == e.schema
Traceback (most recent call last):
  File "<input>", line 1, in <module>
AssertionError

Environment: linux, pyarrow 0.17.0 installed via pipenv
Reporter: Al Taylor
Assignee: Krisztian Szucs / @kszucs

PRs and other links:

• GitHub Pull Request #8004

_{Note: This issue was originally created as ARROW-8773. Please see the migration documentation for further details.}

[asfimport]

Joris Van den Bossche / @jorisvandenbossche:
[~Al Taylor] Thanks for the report.
That's indeed something that should be preserved in the empty_table() method.

A PR to fix this is always welcome!

[asfimport]

Antoine Pitrou / @pitrou:
Issue resolved by pull request 8004
#8004