ObjDict

Objdict, short for object dictionary, is a data structure that combines dictionary semantics with attribute-style access. It allows keys to be retrieved and assigned using both the standard dictionary syntax (obj['key']) and dot notation (obj.key). This dual access can simplify working with nested, JSON-like data.

Implementation typically involves subclassing a dictionary or wrapping a dict and routing attribute access to keys. The core idea is to map attribute access to dictionary lookup: __getattr__ returns self[key] when present, and __setattr__ stores values into self[key]. To preserve convenient dot-notation for nested data, many implementations convert nested dictionaries into ObjDict instances recursively, so deeper levels also support dot notation.

Usage and advantages: Objdicts are handy for configuration objects, data models, and quick prototyping when data resemble JSON. They improve readability and reduce boilerplate by eliminating the need for repetitive key-based lookups and can make code feel more expressive when keys are valid identifiers.

Limitations and caveats: Attribute access can clash with existing object attributes or methods, and keys that are not valid Python identifiers may require bracket notation. Performance is typically slower than plain dict access, and behavior for missing keys can differ between implementations (some raise AttributeError, others KeyError). Some variants offer read-only modes or strict key validation to mitigate surprises.

Variants and context: The concept appears in multiple languages and libraries under names like ObjectDict or objdict. It is a pattern rather than a standardized type, valued for convenience but requiring awareness of potential namespace conflicts and serialization implications.