copy-on-write

1 trace

• pandas 3: chained assignment df['a'][mask] = v silently does nothing (Copy-on-Write); SettingWithCopyWarning is gone
  After upgrading to pandas 3.0, code like df["foo"][df["bar"] > 5] = 100 or df["foo"].replace(1, 5, inplace=True) / df["col"].fillna(0, inplace=True) no longer updates df (a ChainedAssignmentError warning is emitted…
  Gotchano outcome reports yetpandas@32026-01-21