[Python] Missing bindings for existing_data_behavior makes it impossible to maintain old behavior #30165
Description
6.0.0 added support for existing_data_behavior but not bindings for it (see ARROW-13703). Since the default behavior changed to error if there is existing data there is no way to override this new default behavior.
Reporter: Weston Pace / @westonpace
Assignee: Weston Pace / @westonpace
PRs and other links:
Note: This issue was originally created as ARROW-14620. Please see the migration documentation for further details.