I like to conver : to - but - to _ but not : to _

[wallebot1]

{':': '-'}
I like to conver : to - but - to _ but not : to _
Or equivalent
I like to conver (: -> - ) but (- -> _) but not (: -> _)

I have a problem for undesirable conversion.
I think (separator="_") works after translate and pretranslate and if works in pretranslate -> separator -> translate problem is solved.
Note: i don't know why translate need a funtion and don't work with a dict.

Separator convert ":" to a "" (pre) and (translate) don`t prevent this.
(safe_chars=":") prevent ":" -> "" conversion but then conversion ":" -> "-" is made and conversion "-" -> "" is made.
Eventualy undesirable conversion ":" -> "" is made.
I can prevent this adding "-" to safe_chars=, but i like to convert "-" -> "", But Not ":" -> ""

I think separator should ignore pre or translate.keys()

I hope i'm sucesfull explaining.

Thanks for awesome-slugify, is awesome :) and with interesting features.