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qnd.adict module

An items-as-attributes dict.

class qnd.adict.ADict(*args, **kwargs)[source]

Bases: qnd.adict.ItemsAreAttrs, dict

Subclass of dict permitting access to items as if they were attributes.

For a ADict ad, ad.x is equivalent to ad['x'] for getting, setting, or deleting items. The exceptions are dict method names, like keys or items, syntactically illegal names, like class or yield, and any name beginning with __.

Additionally, as a work around for some of these exceptions, ADict will remove a single trailing underscore from an attribute name, so ad.x_ is also equivalent to ad['x'], and you need ad.x__ to get ad['x_'] (a convention inspired by the similar PEP8 recommendation for syntatically illegal variable names). The trailing underscore removal does not apply to names beginning with __.

The trailing underscore removal convention applies to keywords passed to the constructor or to the update method as well.

Use subscript syntax when a variable or expression holds an item name; use attribute syntax when you know the item name at parse time:

ad[variable] = value  # value of variable is the item name
ad.fixed = value  # 'fixed' is the item name
value = ad.get('fixed', default)  # except to avoid KeyError

See also

redict
recursively toggle between dict and ADict
ItemsAreAttrs
mixin base class to provide this for any class
class qnd.adict.ItemsAreAttrs[source]

Bases: object

Mix-in class for QArray, QGroup, or QList, and also ADict.

update(*args, **kwargs)[source]

Multiple __setitem__ from positional arguments or keywords.

qnd.adict.redict(d, cls=None)[source]

Recursively convert a nested dict to a nested ADict and vice versa.

Parameters:
  • d (dict or ADict instance) – A dict, possibly nested, to be converted.
  • cls (dict or subclass of dict, optional) – The dict-like cls to recursively convert d and any sub-dicts into. By default, if d is a ADict, cls is dict, otherwise cls is ADict, so repeated calls to redict toggle between dict and ADict.
Returns:

dnew – A copy of d whose class is cls. Any items which are dict instances are similarly copied to be cls instances. Non-dict items are not copied unless assignment makes copies.
Return type:

dict or ADict