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[jira] [Created] (ARROW-4032) [Python] New pyarrow.Table.from_pydict() function


David Lee created ARROW-4032:
--------------------------------

             Summary: [Python] New pyarrow.Table.from_pydict() function
                 Key: ARROW-4032
                 URL: https://issues.apache.org/jira/browse/ARROW-4032
             Project: Apache Arrow
          Issue Type: Task
          Components: Python
            Reporter: David Lee


Here's a proposal to create a pyarrow.Table.from_pydict() function.

Right now only pyarrow.Table.from_pandas() exist and there are inherit problems using Pandas with NULL support for Int(s) and Boolean(s)

[http://pandas.pydata.org/pandas-docs/version/0.23.4/gotchas.html]

{{NaN}}, Integer {{NA}} values and {{NA}} type promotions:

Sample python code on how this would work.

 
{code:java}
import pyarrow as pa
from datetime import datetime

pylist = [
{"name": "Tom", "age": 10},
{"name": "Mark", "age": 5, "city": "San Francisco"},
{"name": "Pam", "age": 7, "birthday": datetime.now()}
]

def from_pydict(pylist, columns):
    arrow_columns = list()
    for column in columns:
        arrow_columns.append(pa.array([v[column] if column in v else None for v in pylist]))
    arrow_table = pa.Table.from_arrays(arrow_columns, columns)
    return arrow_table

test = from_pydict(pylist, ['name' , 'age', 'city', 'birthday', 'dummy'])

{code}
 



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