Transients and Internal OptionsΒΆ

Some options do not make sense as permanent values–they are needed only as transient settings in the context of individual method calls. The special null value Transient can be assigned as an option value to signal this.

Other options are useful, but only internal to your class. They are not meant to be exposed as part of the external API. In this case, they can be signified by prefixing with an underscore, such as _cached_value. This is consistent with Python naming practice.