[ARROW-17774] [Python] write csv decimal cast error

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 8.0.0
• Fix Version/s: 11.0.0
• Component/s: C++
• Labels: pull-request-available
• External issue URL: https://github.com/apache/arrow/issues/33002
• Assignee: Miles Granger
• Reporter: Alejandro Marco Ramos
• Created: 19/Sep/22 18:13
• Updated: 11/Jan/23 11:55
• Resolved: 27/Oct/22 09:41

Description

Hi, when try to write table with any field in `Decimal128` type, arrow raises with this message:

In [136]: ds.write_dataset(table, "data", format="csv")
---------------------------------------------------------------------------
ArrowNotImplementedError                  Traceback (most recent call last)
Cell In [136], line 1
----> 1 ds.write_dataset(table, "data", format="csv")

File c:\users\documents\projects\.venv\lib\site-packages\pyarrow\dataset.py:930, in write_dataset(data, base_dir, basename_template, format, partitioning, partitioning_flavor, schema, filesystem, file_options, use_threads, max_partitions, max_open_files, max_rows_per_file, min_rows_per_group, max_rows_per_group, file_visitor, existing_data_behavior, create_dir)
    927         raise ValueError("Cannot specify a schema when writing a Scanner")
    928     scanner = data
--> 930 _filesystemdataset_write(
    931     scanner, base_dir, basename_template, filesystem, partitioning,
    932     file_options, max_partitions, file_visitor, existing_data_behavior,
    933     max_open_files, max_rows_per_file,
    934     min_rows_per_group, max_rows_per_group, create_dir
    935 )

File c:\users\documents\projects\.venv\lib\site-packages\pyarrow\_dataset.pyx:2737, in pyarrow._dataset._filesystemdataset_write()

File c:\users\documents\projects\.venv\lib\site-packages\pyarrow\error.pxi:121, in pyarrow.lib.check_status()

ArrowNotImplementedError: Unsupported cast from decimal128(21, 15) to utf8 using function cast_string

my data is:

In [137]: table
Out[137]: 
pyarrow.Table
col1: int64
col2: double
col3: decimal128(21, 15)
col4: string
----
col1: [[1,2,3,0]]
col2: [[2.7,0,3.24,3]]
col3: [[-304236.460000000000000,0.E-15,0.E-15,0.E-15]]
col4: [["primera","segunda","tercera","cuarta"]]

 

Thanks in advance.

Issue Links

• relates to: ARROW-17458 [C++] CSV Writer: Unsupported cast from decimal to utf8
• links to: GitHub Pull Request #14525