资料来源 : pyDict

可选择地

资料来源 : Webster's Revised Unabridged Dictionary (1913)

Optionally \Op"tion*al*ly\, adv.
   In an optional manner.

资料来源 : WordNet®

optionally
     adv : in an optional manner; "this rule is applied optionally"
           [ant: {obligatorily}]