[jira] [Commented] (ARROW-6582) [R] Arrow to R fails with embedded nuls in strings

["Ian Cook (Jira)" <ji...@apache.org>]

    [ https://issues.apache.org/jira/browse/ARROW-6582?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17274132#comment-17274132 ] 

Ian Cook commented on ARROW-6582:
---------------------------------

For future reference/testing purposes: attached is a tiny uncompressed Parquet file named {{embedded_nul.parquet}} that contains a single string column named {{x}} with a single record containing a one-byte string consisting of an embedded nul. The file was written with Spark 3.0.1 using this PySpark code:

{code:python}
from pyspark.sql.types import *
schema = StructType([StructField("x", StringType(), True)])
json = '[{"x": "\\u0000"}]}'
df = spark.read.schema(schema).json(sc.parallelize([json]))
df.repartition(1).write.parquet('embedded_nul.parquet', compression = 'none')
{code}

> [R] Arrow to R fails with embedded nuls in strings
> --------------------------------------------------
>
>                 Key: ARROW-6582
>                 URL: https://issues.apache.org/jira/browse/ARROW-6582
>             Project: Apache Arrow
>          Issue Type: Bug
>          Components: R
>    Affects Versions: 0.14.1
>         Environment: Windows 10
> R 3.4.4
>            Reporter: John Cassil
>            Assignee: Neal Richardson
>            Priority: Major
>              Labels: pull-request-available
>             Fix For: 3.0.0
>
>         Attachments: embedded_nul.parquet
>
>          Time Spent: 3h 40m
>  Remaining Estimate: 0h
>
> Apologies if this issue isn't categorized or documented appropriately.  Please be gentle! :)
> As a heavy R user that normally interacts with parquet files using SparklyR, I have recently decided to try to use arrow::read_parquet() on a few parquet files that were on my local machine rather than in hadoop.  I was not able to proceed after several various attempts due to embedded nuls.  For example:
> try({df <- read_parquet('out_2019-09_data_1.snappy.parquet') })
> Error in Table__to_dataframe(x, use_threads = option_use_threads()) : 
>   embedded nul in string: 'INSTALL BOTH LEFT FRONT AND RIGHT FRONT  TORQUE ARMS\0 ARMS'
> Is there a solution to this?
> I have also hit roadblocks with embedded nuls in the past with csvs using data.table::fread(), but readr::read_delim() seems to handle them gracefully with just a warning after proceeding.
> Apologies that I do not have a handy reprex. I don't know if I can even recreate a parquet file with embedded nuls using arrow if it won't let me read one in, and I can't share this file due to company restrictions.
> Please let me know how I can be of any more help!



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