为何Python官方词法分析文档未将赋值运算符=归入运算符类别？第三方教程与官方规范是否存在冲突？

Great question—you’ve nailed a key distinction between Python’s lexical token classification (how the interpreter breaks code into basic building blocks) and the semantic terminology used in most programming tutorials. Let’s unpack this clearly:

1. Lexical Classification vs. Semantic Role #

First, we need to separate two different frameworks:

• Python’s official lexical spec categorizes tokens based on how the parser splits code into chunks (tokenization). This is about the mechanics of how the interpreter reads code.
• Third-party tutorials use terms based on what the syntax does (semantic function). This is about teaching programming concepts in a way that’s intuitive for learners.

These aren’t conflicting—they’re just talking about the same syntax from two different angles. Neither is "wrong."

2. Why = Lives in the Separator Section #

In Python’s lexer, = (along with augmented assignments like +=) is grouped with separators because its primary lexical job is to split code into distinct, parseable parts. For example:

• In x = 5, the = token separates the target variable (x) from the expression being assigned (5).
• This mirrors how commas separate function arguments or colons split dictionary keys from values—they’re structural markers that divide code into logical chunks during parsing.

The note about augmented assignments ("lexically act as separators but also perform operations") applies equally to plain =—it just wasn’t called out explicitly. The lexer sees it as a structural separator first, even though its semantic role is to perform an assignment.

3. Are Third-Party Tutorials Wrong? #

Absolutely not! Calling = an "assignment operator" is a standard, practical teaching term. From a semantic perspective, it behaves like an operator: it takes two operands (a target and a value) and executes an action (assigning the value to the target). This terminology aligns with how most programming languages frame assignment, so it’s a natural way to teach beginners.

The official spec’s classification is focused on under-the-hood parsing mechanics, which isn’t usually the priority for introductory tutorials.

内容的提问来源于stack exchange，提问作者PodGen4