[jira] [Issue Comment Deleted] (ARROW-13939) how to do resampling of arrow table using cython

["krishna deepak (Jira)" <ji...@apache.org>]

     [ https://issues.apache.org/jira/browse/ARROW-13939?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

krishna deepak updated ARROW-13939:
-----------------------------------
    Comment: was deleted

(was: [~willjones127] [~westonpace],

This is what I tried with.
{{}}
{code:java}
// code placeholder
{code}
cdef shared_ptr[CTable] table = pyarrow_unwrap_table(obj)
cdef CTable *table_ptr = table.get()
cdef list timeframes = [3, 5, 15]

if table_ptr == NULL:
 raise TypeError("not an array")

cdef CChunkedArray *column1
cdef CChunkedArray *column2
cdef CArray *array1
cdef CArray *array2
cdef int num_rows = table_ptr.num_rows()
cdef shared_ptr[CSchema] schema = table_ptr.schema()

cdef CResult[shared_ptr[CScalar]] val

column1 = table_ptr.column(0).get()
column2 = table_ptr.column(1).get()

chunk_i = 0
while True:
 array1 = column1.chunk(chunk_i).get()
 # array2 = column2.chunk(chunk_i).get()

 if array1 == NULL:
 break

 length = array1.length()
 val = array1.GetScalar(0)
 if val.ok():
 val.ValueOrDie()

 )

> how to do resampling of arrow table using cython
> ------------------------------------------------
>
>                 Key: ARROW-13939
>                 URL: https://issues.apache.org/jira/browse/ARROW-13939
>             Project: Apache Arrow
>          Issue Type: New Feature
>          Components: C++, Python
>            Reporter: krishna deepak
>            Priority: Minor
>
> Please can someone point me to resources, how to write a resampling code in cython for Arrow table.
>  # Will iterating the whole table be slow in cython?
>  # which is the best to use to append new elements to. Is there a way i create an empty table of same schema and keep appending to it. Or should I use vectors/list and then pass them to create a table.
> Performance is very important for me. Any help is highly appreciated.



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