Set a flag on the function or a global?

[MRAB]

On 2015-06-16 01:24, sohcahtoa82 at gmail.com wrote:
> On Monday, June 15, 2015 at 4:57:53 PM UTC-7, Steven D'Aprano wrote:
>> I have a function in a module which is intended to be used by
>> importing that name alone, then used interactively:
>>
>> from module import edir edir(args)
>>
>>
>> edir is an enhanced version of dir, and one of the enhancements is
>> that you can filter out dunder methods. I have reason to believe
>> that people are split on their opinion on whether dunder methods
>> should be shown by default or not: some people want to see them,
>> others do not. Since edir is meant to be used interactively, I want
>> to give people a setting to control whether they get dunders by
>> default or not.
>>
>> I have two ideas for this, a module-level global, or a flag set on
>> the function object itself. Remember that the usual way of using
>> this will be "from module import edir", there are two obvious ways
>> to set the global:
>>
>> import module module.dunders = False
>>
>> # -or-
>>
>> edir.__globals__['dunders'] = False
>>
>>
>> Alternatively, I can use a flag set on the function object itself:
>>
>> edir.dunders = False
>>
>>
>> Naturally you can always override the default by explicitly
>> specifying a keyword argument edir(obj, dunders=flag).
>>
>> Thoughts and feedback? Please vote: a module global, or a flag on
>> the object? Please give reasons, and remember that the function is
>> intended for interactive use.
>>
>>
>> -- Steven D'Aprano
>
> Using a keyword argument for the edir function is the most intuitive
> and easy to read, IMO.
>
> Also, if two people are working on the same script, it could create
> problems if one person wants to filter them, but the other doesn't.
> That would create a state that they would both have to monitor and
> keep setting back and forth, rather than each one just setting an
> argument on their calls.
>
But it's meant to be used interactively. If they're using it in a
script, they'd most likely set the argument appropriately.