pandas/io/feather_format.py should call use_threads instead of nthreads to prevent breakage in pyarrow 0.11.0

Code Sample

d = {'one' : [1., 2., 3., 4.],
        'two' : [4., 3., 2., 1.]}
df = pandas.DataFrame(d)
df.to_feather('example.feather')

# with pyarrow 0.10.0 this succeeds with a deprecation warning
# with pyarrow 0.11.0 this errors with a TypeError: unexpected argument 'nthreads'
df = pandas.read_feather('example.feather')

# attempt to manually set nthreads results in TypeError: unexpectect argument 'nthreads'
df = pandas.read_feather('example.feather', nthreads=4)

# attempt to pass 'use_threads' results in TypeError: unexpected argument 'nthreads'
df = pandas.read_feather('example.feather', use_threads=True)

Problem description

Pandas introduced nthreads for reading feather files in issue 16359

With PyArrow 0.10.0 a deprecation warning is shown from this source: “nthreads argument is deprecated, pass use_threads instead”

When PyArrow version 0.11.0, Python errors with: TypeError: read_feather() got an unexpected keyword argument ‘nthreads’.

I’ve searched with ‘pyarrow’ and ‘nthreads’ keywords and didn’t see this issue posted.

Specifically feather-format.py line 112 should be changed to return feather.read_dataframe(path, use_threads=True) or changing the method signature to all overriding use_threads: return feather.read_dataframe(path, use_threads=use_threads) I will submit a PR if the only barrier to fix is code effort.

Expected Output

I expect no error output upon running pandas.read_feather() with PyArrow 0.11.0

Output of pd.show_versions()

[paste the output of pd.show_versions() here below this line] INSTALLED VERSIONS

commit: None
python: 3.6.6.final.0
python-bits: 64
OS: Windows
OS-release: 7
machine: AMD64
processor: Intel64 Family 6 Model 79 Stepping 1, GenuineIntel byteorder: little
LC_ALL: None
LANG: None
LOCALE: None.None

pandas: 0.23.4
pytest: None
pip: 18.1
setuptools: 40.3.0
Cython: None
numpy: 1.15.1
scipy: 1.1.0
pyarrow: 0.10.0
xarray: None
IPython: 6.5.0
sphinx: None
patsy: 0.5.0
dateutil: 2.7.3
pytz: 2018.5
blosc: None
bottleneck: None
tables: None
numexpr: None
feather: 0.4.0
matplotlib: 2.2.2
openpyxl: None
xlrd: 1.1.0
xlwt: None
xlsxwriter: None
lxml: None
bs4: None
html5lib: None
sqlalchemy: 1.2.11
pymysql: None
psycopg2: None
jinja2: None
s3fs: None
fastparquet: None
pandas_gbq: None
pandas_datareader: None

[bartolsthoorn]

Work-around might be useful to some people:

import feather
frame = feather.read_dataframe('filename.feather')

[TomAugspurger]

Next version of pandas. Aiming to have it out by the end of the year.

On Tue, Dec 4, 2018 at 12:21 PM Richard Anderson [e-mail] wrote:

#23112 https://github.com/pandas-dev/pandas/pull/23112 So the fix will show up in the next release of pandas/pyarrow?

— You are receiving this because you commented. Reply to this email directly, view it on GitHub https://github.com/pandas-dev/pandas/issues/23053#issuecomment-444203379, or mute the thread https://github.com/notifications/unsubscribe-auth/ABQHIm_1ZurasUJ0Yaj33q1K2sH_NGT-ks5u1r0LgaJpZM4XPmBW .