[ARROW-4563] [Python] pa.decimal128 should validate inputs

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 0.12.0
• Fix Version/s: 0.13.0
• Component/s: Python
• Labels: pull-request-available
• External issue URL: https://github.com/apache/arrow/issues/21109
• Assignee: Antoine Pitrou
• Reporter: Antoine Pitrou
• Created: 13/Feb/19 19:17
• Updated: 11/Jan/23 07:34
• Resolved: 14/Feb/19 20:21

Description

The precision shouldn't be higher than 38, but 39 is happily accepted currently:

>>> ty = pa.decimal128(39, 0)                                                                            
>>> arr = pa.array([2**127], type=ty)                                                                  
>>> arr                                                                                                  
<pyarrow.lib.Decimal128Array object at 0x7f9b89444138>
[
  -170141183460469231731687303715884105728
]

Issue Links

• Blocked: ARROW-4569 [Gandiva] validate that the precision/scale are within bounds
• supercedes: ARROW-3904 [C++/Python] Validate scale and precision of decimal128 type
• links to: GitHub Pull Request #3647