Multidicts are useful for working with HTTP headers, URL query args etc.
The code was extracted from aiohttp library.
HTTP Headers and URL query string require specific data structure:
multidict. It behaves mostly like a regular dict but it may have
several values for the same key and preserves insertion ordering.
The key is str (or istr for case-insensitive dictionaries).
multidict has four multidict classes:
MultiDict, MultiDictProxy, CIMultiDict
and CIMultiDictProxy.
Immutable proxies (MultiDictProxy and
CIMultiDictProxy) provide a dynamic view for the
proxied multidict, the view reflects underlying collection changes. They
implement the collections.abc.Mapping interface.
Regular mutable (MultiDict and CIMultiDict) classes
implement collections.abc.MutableMapping and allows to change
their own content.
Case insensitive (CIMultiDict and
CIMultiDictProxy) ones assume the keys are case
insensitive, e.g.:
>>> dct = CIMultiDict(key='val') >>> 'Key' in dct True >>> dct['Key'] 'val'
Keys should be str or istr instances.
The library has optional Cython optimization for sake of speed.
Apache 2