[jira] [Commented] (ARROW-15252) [R] Expose skip_rows_after in CSVReadOptions

["Martin du Toit (Jira)" <ji...@apache.org>]

    [ https://issues.apache.org/jira/browse/ARROW-15252?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17469241#comment-17469241 ] 

Martin du Toit commented on ARROW-15252:
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Hi [~thisisnic] , thanks for getting back to me. 

I also tried it with pyarrow, although not my preferred language, but got the same error. Is it possible with pyarrow, or also not exposed to pyarrow?

> [R] Expose skip_rows_after in CSVReadOptions 
> ---------------------------------------------
>
>                 Key: ARROW-15252
>                 URL: https://issues.apache.org/jira/browse/ARROW-15252
>             Project: Apache Arrow
>          Issue Type: Improvement
>          Components: R
>            Reporter: Martin du Toit
>            Assignee: Nicola Crane
>            Priority: Major
>         Attachments: I2478172_Activity_20180830.csv
>
>
> Not sure if this is a bug, but if I open_dataset of a directory containing csv files with a header and a footer, I specify the following convert options to include_missing_columns. The code works fine on files with no header and footer
> {code:r}
> col_names <- c("col names specified as in 2nd row of file") #ie colnames is known
> skip <- 2
> file_path <- "path to directory holding various files"
> #schema_file <- created using arrow::schema
> #schema_df<- created using arrow::schema but with extra columns for the .partition_cols
> conv_options <- CsvConvertOptions$create(strings_can_be_null = TRUE, include_missing_columns = TRUE, include_columns = col_names) 
> read_options <- arrow:::readr_to_csv_read_options(skip, col_names)
> format <- arrow::FileFormat$create(format = "text", schema = schema_file, convert_options = conv_options, read_options  = read_options)
> ds <- arrow::open_dataset(sources = file_path, schema = schema_df, partitioning = .partition_cols, format = format){code}
> The dataset gets created, but any further operation on the dataset fail with
> {code:r}
> Error: Invalid: CSV parse error: Row #7: Expected 41 columns, got 3: T,7,
> {code}



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