multilookupdict 0.1.3

A dict-like container that allows multiple keys to address the same value.

Multi-Lookup-Dict

A Dict-like container that allows multiple keys to address the same value.

>>> d = MultiLookupDict()
>>> d["a_key"] = "some_value"
>>> d.map_key("a_key", "another_key") # Make "another_key" an alias of "a_key"

Implemented as two dicts:
    - `MultiLookupDict._data` holds the 'canonical key' and value
    - `MultiLookupDict._key_to_canonical_map` maps 'alias keys' onto canonical keys.
        (Canonical keys are mapped to themselves in this dict)

Externally, all keys (canonical and alias) are treated identically, and all refer to the same value, unless a key is reassigned to another value using map_key.

Multi-key lookups and assignments

Iterables of keys can also be accessed, set, and mapped.

>>> d = MultiLookupDict()
>>> d[("key_a", "key_b", "key_c")] = "some_value"
>>> d["key_a"] == "some_value"

Where items are accessed with multiple keys, all distinct matching values are returned
as a list (where multiple keys are requested, the result is always a list, for consistency)

>>> d["key_d"] = "some_other_value" # Add a distinct value
>>> d[("key_a", "key_b", "key_d")] == ["some_value", "some_other_value"]


>>> d.map_key("key_a", ("key_e", "key_f")) # Also do multiple mappings

...

Methods

setitem Sets a key to the value. If a (non-string) iterable is provided as key, each key will be assigned the value. getitem [As with standard Python dict] map_key Assign the value of one key to another key. Both keys now point to the same value. keys Returns all keys in MultiLookupDict. Returned keys refer to same or different objects. all_keys [Same as keys] values [Same as dict.values] items Same as dict.items, except key part of tuple is a set of keys for the corresponding value pop Same as dict.pop. All keys pointing to value are removed. aliases Returns all aliases of a given key