[
https://issues.apache.org/jira/browse/ARROW-1976?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16351593#comment-16351593
]
ASF GitHub Bot commented on ARROW-1976:
---------------------------------------
wesm commented on issue #1553: ARROW-1976: [Python] Handling unicode pandas
columns on parquet.read_table
URL: https://github.com/apache/arrow/pull/1553#issuecomment-362870812
Any chance anyone has time to look at getting our CI rehabilitated so we can
get a passing CI build? https://github.com/apache/arrow/pull/1548 still has
some Windows issues
----------------------------------------------------------------
This is an automated message from the Apache Git Service.
To respond to the message, please log on GitHub and use the
URL above to go to the specific comment.
For queries about this service, please contact Infrastructure at:
[email protected]
> [Python] Handling unicode pandas columns on parquet.read_table
> --------------------------------------------------------------
>
> Key: ARROW-1976
> URL: https://issues.apache.org/jira/browse/ARROW-1976
> Project: Apache Arrow
> Issue Type: Bug
> Components: Python
> Affects Versions: 0.8.0
> Reporter: Simbarashe Nyatsanga
> Assignee: Licht Takeuchi
> Priority: Major
> Labels: pull-request-available
> Fix For: 0.9.0
>
>
> Unicode columns in pandas DataFrames aren't being handled correctly for some
> datasets when reading a parquet file into a pandas DataFrame, leading to the
> common Python ASCII encoding error.
>
> The dataset used to get the error is here:
> https://catalog.data.gov/dataset/college-scorecard
> {code}
> import numpy as np
> import pandas as pd
> import pyarrow as pa
> import pyarrow.parquet as pq
> df = pd.read_csv('college_data.csv')
> {code}
> For verification, the DataFrame's columns are indeed unicode
> {code}
> df.columns
> > Index([u'UNITID', u'OPEID', u'OPEID6', u'INSTNM', u'CITY', u'STABBR',
> u'INSTURL', u'NPCURL', u'HCM2', u'PREDDEG',
> ...
> u'RET_PTL4', u'PCTFLOAN', u'UG25ABV', u'MD_EARN_WNE_P10', u'GT_25K_P6',
> u'GRAD_DEBT_MDN_SUPP', u'GRAD_DEBT_MDN10YR_SUPP', u'RPY_3YR_RT_SUPP',
> u'C150_L4_POOLED_SUPP', u'C150_4_POOLED_SUPP'],
> dtype='object', length=123)
> {code}
> The DataFrame can be saved into a parquet file
> {code}
> arrow_table = pa.Table.from_pandas(df)
> pq.write_table(arrow_table, 'college_data.parquet')
> {code}
> But trying to read the parquet file immediately afterwards results in the
> following
> {code}
> df = pq.read_table('college_data.parquet').to_pandas()
> > ---------------------------------------------------------------------------
> UnicodeEncodeError Traceback (most recent call last)
> <ipython-input-29-23906ea1efe3> in <module>()
> ----> 2 df = pq.read_table('college_data.parquet').to_pandas()
> /Users/anaconda/envs/env/lib/python2.7/site-packages/pyarrow/table.pxi in
> pyarrow.lib.Table.to_pandas
> (/Users/travis/build/BryanCutler/arrow-dist/arrow/python/build/temp.macosx-10.6-intel-2.7/lib.cxx:46331)()
> 1041 if nthreads is None:
> 1042 nthreads = cpu_count()
> -> 1043 mgr = pdcompat.table_to_blockmanager(options, self,
> memory_pool,
> 1044 nthreads)
> 1045 return pd.DataFrame(mgr)
> /Users/anaconda/envs/env/lib/python2.7/site-packages/pyarrow/pandas_compat.pyc
> in table_to_blockmanager(options, table, memory_pool, nthreads, categoricals)
> 539 if columns:
> 540 columns_name_dict = {
> --> 541 c.get('field_name', str(c['name'])): c['name'] for c in
> columns
> 542 }
> 543 columns_values = [
> /Users/anaconda/envs/env/lib/python2.7/site-packages/pyarrow/pandas_compat.pyc
> in <dictcomp>((c,))
> 539 if columns:
> 540 columns_name_dict = {
> --> 541 c.get('field_name', str(c['name'])): c['name'] for c in
> columns
> 542 }
> 543 columns_values = [
> UnicodeEncodeError: 'ascii' codec can't encode character u'\ufeff' in
> position 0: ordinal not in range(128)
> {code}
> Looking at the stacktrace , it looks like this line, which is using str which
> by default will try to do ascii encoding:
> https://github.com/apache/arrow/blob/master/python/pyarrow/pandas_compat.py#L541
--
This message was sent by Atlassian JIRA
(v7.6.3#76005)
