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https://issues.apache.org/jira/browse/ARROW-10324?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17215444#comment-17215444
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Neal Richardson commented on ARROW-10324:
-----------------------------------------
This is the same as ARROW-6582. We're working on a proper solution but don't
have one yet. Two things to note:
1. In the upcoming release, it won't error anymore, it will truncate the string
at the nul. Arguably that's worse because you won't know you have a problem.
2. I think you can work around this by reading with {{as_data_frame = FALSE}}
as you have done, and then cast the offending column(s) to {{binary()}} before
bringing the data into R. That will give you a list of raw vectors, and you
should be able to filter out the {{00}}s and then call {{rawToChar()}} on them
(assuming what you want is to drop the nuls).
> function read_parquet(*,as_data_frame=TRUE) fails when embedded nuls present.
> ------------------------------------------------------------------------------
>
> Key: ARROW-10324
> URL: https://issues.apache.org/jira/browse/ARROW-10324
> Project: Apache Arrow
> Issue Type: Improvement
> Components: R
> Reporter: Akash Shah
> Priority: Major
>
> For the following code snippet
> {code:java}
> // code placeholder
> library(arrow)
> download.file('https://github.com/akashshah59/embedded_nul_parquet/raw/main/CC-MAIN-20200702045758-20200702075758-00007.parquet','sample.parquet')
> read_parquet(file = 'sample.parquet',as_data_frame = TRUE)
> {code}
> I get -
>
> {code:java}
> Error in Table__to_dataframe(x, use_threads = option_use_threads()) :
> embedded nul in string: '\0 at \0'
> {code}
>
> So, I thought, what if I could read the file as binaries and replace the
> embedded nul character \0 myself.
>
> {code:java}
> parquet <- read_parquet(file = 'sample.parquet',as_data_frame = FALSE)
> raw <- write_to_raw(parquet,format = "file")
> print(raw){code}
>
> In this case, I get an indecipherable stream of characters and nuls, which
> makes it very difficult to remove '00' characters that are problematic in the
> stream.
>
> {code:java}
> [1] 41 52 52 4f 57 31 00 00 ff ff ff ff d0 02 00 00 10 00 00 00 00 00 0a 00
> 0c 00 06 00
> [29] 05 00 08 00 0a 00 00 00 00 01 04 00 0c 00 00 00 08 00 08 00 00 00 04 00
> 08 00 00 00
> [57] 04 00 00 00 0d 00 00 00 70 02 00 00 38 02 00 00 10 02 00 00 d0 01 00 00
> a4 01 00 00
> [85] 74 01 00 00 34 01 00 00 04 01 00 00 cc 00 00 00 9c 00 00 00 64 00 00 00
> 34 00 00 00
> [113] 04 00 00 00 d4 fd ff ff 00 00 01 05 14 00 00 00 0c 00 00 00 04 00 00 00
> 00 00 00 00
> [141] c4 fd ff ff 0a 00 00 00 77 61 72 63 5f 6c 61 6e 67 73 00 00 00 fe ff ff
> 00 00 01 05
> [169] 14 00 00 00 0c 00 00 00 04 00 00 00 00 00 00 00 f0 fd ff ff 0b 00 00 00
> 6c 61 6e 67
> [197] 5f 64 65 74 65 63 74 00 2c fe ff ff 00 00 01 03 18 00 00 00 0c 00 00 00
> 04 00
> {code}
>
> Is there a way to handle this while reading Apache parquet?
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