[ARROW-2453] [Python] Improve Table column access

• Type: Improvement
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 0.9.0
• Fix Version/s: 0.10.0
• Component/s: Python
• Labels: beginner pull-request-available
• External issue URL: https://github.com/apache/arrow/issues/18607
• Assignee: Kee Chong Tan
• Reporter: Antoine Pitrou
• Created: 13/Apr/18 09:40
• Updated: 11/Jan/23 07:21
• Resolved: 21/Apr/18 20:22

Description

Suppose you have a table column named "nulls". Right now, to access it on a table, you need to do something like this:

>>> table.column(table.schema.get_field_index('nulls'))
<pyarrow.lib.Column object at 0x7fe4144d2570>
chunk 0: <pyarrow.lib.NullArray object at 0x7fe3db51b4a8>
[
  NA,
  NA,
  NA
]

Also, if you mistype the column name, instead of getting an error you get an arbitrary column:

>>> table.column(table.schema.get_field_index('z'))
<pyarrow.lib.Column object at 0x7fe3dbd6cc30>
chunk 0: <pyarrow.lib.Int64Array object at 0x7fe3db54b408>
[
  0,
  1,
  2
]

Table.column() should accept a string object and return the column with the corresponding name. KeyError should be raised if there is no column with a such name.

Issue Links

• links to: GitHub Pull Request #1923