@lezer/python

What is @lezer/python?

@lezer/python is a parser for the Python programming language built using the Lezer parser system. It is designed to be used in syntax highlighting, code analysis, and other language processing tasks.

What are @lezer/python's main functionalities?

Parsing Python Code

This feature allows you to parse Python code into a syntax tree. The code sample demonstrates how to parse a simple Python function and print the resulting syntax tree.

const {parser} = require('@lezer/python');
const input = 'def hello():\n    print("Hello, world!")';
const tree = parser.parse(input);
console.log(tree.toString());

Syntax Highlighting

This feature allows you to use the parsed syntax tree for syntax highlighting. The code sample shows how to highlight a simple Python function using CodeMirror's highlighting utilities.

const {parser} = require('@lezer/python');
const {highlightTree} = require('@codemirror/highlight');
const {defaultHighlightStyle} = require('@codemirror/highlight');
const input = 'def hello():\n    print("Hello, world!")';
const tree = parser.parse(input);
const highlights = highlightTree(tree, defaultHighlightStyle);
console.log(highlights);

Code Analysis

This feature allows you to perform code analysis on the parsed syntax tree. The code sample demonstrates a simple analysis that counts the number of function definitions in the input Python code.

const {parser} = require('@lezer/python');
const input = 'def hello():\n    print("Hello, world!")';
const tree = parser.parse(input);
// Example analysis: count function definitions
let functionCount = 0;
tree.cursor().iterate(node => {
  if (node.name === 'FunctionDefinition') functionCount++;
});
console.log(`Number of functions: ${functionCount}`);

Other packages similar to @lezer/python

tree-sitter-python

tree-sitter-python is a parser for Python built using the Tree-sitter parsing library. It provides similar functionality to @lezer/python, including parsing Python code into syntax trees and enabling syntax highlighting and code analysis. Tree-sitter is known for its efficiency and is widely used in various text editors and IDEs.

esprima

esprima is a high-performance, standard-compliant ECMAScript parser. While it is designed for JavaScript rather than Python, it offers similar capabilities in terms of parsing code into syntax trees and enabling code analysis and syntax highlighting. It is a good example of a parser for a different language with similar functionalities.

acorn

acorn is a small, fast, JavaScript-based parser for ECMAScript. Like @lezer/python, it can parse code into syntax trees and is used for syntax highlighting and code analysis. Acorn is known for its speed and efficiency, making it a popular choice for JavaScript parsing tasks.

README

@lezer/python

This is a Python grammar for the Lezer parser system.

The code is licensed under an MIT license.

Changelog

1.1.14 (2024-05-25)

Bug fixes

Allow dotted names and list of imports in import statements.