[backport 2.3.x] BUG: fix fill value for gouped sum in case of unobserved categories for string dtype (empty string instead of 0) (#61909)#61963

Merged

jorisvandenbossche merged 6 commits intopandas-dev:2.3.xfrom

jorisvandenbossche:backport-61909

Sep 5, 2025

Commits on Jul 26, 2025

BUG: fix fill value for gouped sum in case of unobserved categories for string dtype (empty string instead of 0) (#61909)
jorisvandenbossche
committed

Commits on Aug 18, 2025

Merge branch '2.3.x' into backport-61909
rhshadrach
authored

Commits on Aug 20, 2025

fix reindex to work for string dtype
jorisvandenbossche
committed

Commits on Sep 5, 2025