{"library":"nulltype","title":"NullType Sentinels","description":"nulltype is a Python library (current version 2.3.1) that provides custom null values and sentinels, distinct from Python's built-in `None`, `False`, or `True`. It helps represent different states of 'emptiness' or 'undefined' values, such as `Passthrough`, `Prohibited`, or `Undefined`, without overloading standard Python nullish objects. The library aims to simplify code by allowing robust handling of potentially missing data in a consistent way. The last release was in June 2018, indicating a maintenance phase with infrequent updates.","language":"python","status":"maintenance","last_verified":"Thu May 14","install":{"commands":["pip install nulltype"],"cli":null},"imports":["from nulltype import NullType","from nulltype import Empty","from nulltype import Null","from nulltype import Nothing"],"auth":{"required":false,"env_vars":[]},"quickstart":{"code":"from nulltype import NullType, Empty, Nothing, Null\n\n# Create a custom null type\nUndefined = NullType('Undefined')\n\n# Test common Pythonic behaviors\nassert bool(Undefined) is False\nassert len(Undefined) == 0\nassert list(Undefined) == []\n\n# Accessing attributes, items, or calling a NullType instance\n# By default, for custom NullTypes, attribute/call access returns Empty, and item access returns Nothing.\n# For predefined sentinels like Empty, these operations return themselves.\nassert Undefined.some_attribute is Empty\nassert Undefined[22] is Nothing\nassert Undefined(\"hey\", 12) is Empty\n\n# Using pre-defined sentinels\nassert Empty.any_attr is Empty\nassert Nothing[0] is Nothing\nassert Null() is Null\n\nprint(\"NullType examples ran successfully!\")","lang":"python","description":"Demonstrates how to create a custom `NullType` and its behavior when subjected to common Python operations (boolean evaluation, length, iteration, attribute access, item access, and calls). 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