[GitHub] [arrow] drin commented on issue #14116: Python dict to map

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drin commented on issue #14116:
URL: https://github.com/apache/arrow/issues/14116#issuecomment-1247235473

   I believe the problem is that you are incorrectly providing data to 
`from_pylist` and you are incorrectly structuring the data for `tags`.
   
   Here is a code snippet that I think does what you're looking for:
   ```python
   from pyarrow import Table
   from pyarrow import int64, map_, schema, string, field
   
   def test_map_type():
       # 2 column schema; a map array is a list of tuples
       pyarrow_schema = schema([
            field('id'  , int64()                 , False)
           ,field('tags', map_(string(), string()), False)
       ])
   
       # each row should have: <key count> <= <column count>
       first_row ={
            'id'  : 1
           ,'tags': [
                 ('tag1', 'value1')
                ,('tag2', 'value2' )
            ]
       }
       second_row = {
            'id'  : 2
           ,'tags': [
                 ('tag1', 'value1')
                ,('tag2', 'value2' )
            ]
       }
   
       tags_updated = [first_row, second_row]
       table        = Table.from_pylist(mapping=tags_updated, 
schema=pyarrow_schema)
   
       print(table.to_pydict())
   
   test_map_type()
   ```
   
   output:
   ```bash
   >> python test.py
   {'id': [1, 2], 'tags': [[('tag1', 'value1'), ('tag2', 'value2')], [('tag1', 
'value1'), ('tag2', 'value2')]]}
   ```


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