Allow specifying comment character for CSV reader #5759
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This patch adds reader support for a comment character for reading CSV
files. While comments like almost nothing around the CSV format are not
truly standardized, a common format supported by many CSV
readers[^1][^2] is to ignore full lines starting with a comment
character (often `#`); inline or end of line comments are not supported.
Example:
# This is a comment in a CSV file without header.
1,2
# Comment inside the data block.
11,22
The implementation of this for Arrow is pretty straight-forward as all
we need to do is expose the existing `comment` option of `csv_core` used
to read CSV files.
Closes apache#5758.
[^1]: https://pandas.pydata.org/pandas-docs/stable/reference/api/pandas.read_csv.html
[^2]: https://stat.ethz.ch/R-manual/R-devel/library/utils/html/read.table.html
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bbannier
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May 12, 2024
This commit switches to used version of arrow-rs to the version of apache/arrow-rs#5759 which introduces support for comments in CSV input files.
bbannier
added a commit
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that referenced
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May 12, 2024
This commit switches to used version of arrow-rs to the version of apache/arrow-rs#5759 which introduces support for comments in CSV input files.
bbannier
added a commit
to bbannier/datafusion
that referenced
this pull request
May 12, 2024
This commit switches to used version of arrow-rs to the version of apache/arrow-rs#5759 which introduces support for comments in CSV input files.
tustvold
approved these changes
May 13, 2024
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This patch adds reader support for a comment character for reading CSV files. While comments like almost nothing around the CSV format are not truly standardized, a common format supported by many CSV readers12 is to ignore full lines starting with a comment character (often
#); inline or end of line comments are not supported.Example:
The implementation of this for Arrow is pretty straight-forward as all we need to do is expose the existing
commentoption ofcsv_coreused to read CSV files.Closes #5758.
Footnotes
https://pandas.pydata.org/pandas-docs/stable/reference/api/pandas.read_csv.html ↩
https://stat.ethz.ch/R-manual/R-devel/library/utils/html/read.table.html ↩