This is a port of [python's defaultdict](https://docs.python.org/2/library/collections.html#defaultdict-objects) to JavaScript. It uses proxies to create objects that return values other than ```undefined``` for attributes that haven't yet been set.

defaultdict -----------

Python's defaultdict data structure for JavaScript

A JavaScript implementation of Pythons `defaultdict`.

Zero-dependency typed MultiMap and SetMultiMap — one key, many values. Inspired by Java Guava's Multimap and Python's defaultdict(list).

Dictionary-like object with a handler for missing keys

Simple but useful hacks for everyday javascript programming

TypeScript port of the Java library PinIn for Chinese text match using Pinyin - 用于各类汉语拼音匹配问题的库

Python's collections library for JavaScript

A Map subclass that automatically adds missing values

Modify the internal behaviour of your JavaScript classes

a Util Library for any TypeScript Project

Terminal practice tool for building muscle memory and fluency with the syntax and idioms of JavaScript, Python, and more. Drill methods, run exercises, and resume mid-session.

word frequency

Python standard library for TypeScript - itertools, functools, collections, datetime, re, and more. Zero dependencies. Full TypeScript support.

Helpful collections shamelessly copied from Python and ported to JS: orhttps://docs.python.org/2/library/collections.html#module-collections

Simple solution to this problem: "TypeError: Cannot set property 'x' of undefined"

An extension of Map that auto-initializes new values with empty collections and auto-removes empty collections being set