None

None is a word in English used to express the absence of quantity, value, or person. It can function as a determiner, pronoun, or adverb. It appears in statements such as "None of the cookies remain" or "I have none," where the meaning is “not any” or “no one,” depending on the context.

Etymology traces None to Old English nān, from ne + ān meaning “not one.” Over time its sense broadened to cover “not any” and “no one.” The form has remained relatively stable in modern English, with its usage expanding across determiner, pronoun, and adverb positions.

In computing, None often denotes a special value representing the absence of a value or undefined state. The most widely known example is Python’s None, a singleton of type NoneType used to signal missing data, default arguments, or end-of-iteration signals. It is distinct from False, 0, or empty containers, and evaluates to False in boolean contexts. Other languages use analogous concepts such as null or Nothing. When interfacing with databases, None is commonly mapped to a NULL value.

In databases and data science, NULL represents missing data. Some frameworks and languages treat None and NULL interchangeably, while others distinguish between empty or zero values and truly missing data. Handling these representations requires care to avoid type errors or misinterpretation during data processing and analysis.

Usage notes reflect its flexibility: None can pair with both singular and plural nouns depending on meaning. For example, “None of the evidence is conclusive” uses singular agreement, while “None of the cookies are fresh” uses plural. In general, None signals absence, nonexistence, or the lack of a specified value.