pyrox.dev
1# Python Tree Sitter {#python-tree-sitter}
2
3[Tree Sitter](https://tree-sitter.github.io/tree-sitter/) is a framework for building grammars for programming languages. It generates and uses syntax trees from source files, which are useful for code analysis, tooling, and syntax highlighting.
4
5Python bindings for Tree Sitter grammars are provided through the [py-tree-sitter](https://github.com/tree-sitter/py-tree-sitter) module. The Nix package `python3Packages.tree-sitter-grammars` provides pre-built grammars for various languages.
6
7For example, to experiment with the Rust grammar, you can create a shell environment with the following configuration:
8
9```nix
10{
11 pkgs ? import <nixpkgs> { },
12}:
13
14pkgs.mkShell {
15 name = "py-tree-sitter-dev-shell";
16
17 buildInputs = with pkgs; [
18 (python3.withPackages (
19 ps: with ps; [
20 tree-sitter
21 tree-sitter-grammars.tree-sitter-rust
22 ]
23 ))
24 ];
25}
26```
27
28Once inside the shell, the following Python code demonstrates how to parse a Rust code snippet:
29
30```python
31# Import the Tree Sitter library and Rust grammar
32import tree_sitter
33import tree_sitter_rust
34
35# Load the Rust grammar and initialize the parser
36rust = tree_sitter.Language(tree_sitter_rust.language())
37parser = tree_sitter.Parser(rust)
38
39# Parse a Rust snippet
40tree = parser.parse(
41 bytes(
42 """
43 fn main() {
44 println!("Hello, world!");
45 }
46 """,
47 "utf8"
48 )
49)
50
51# Display the resulting syntax tree
52print(tree.root_node)
53```
54
55The `tree_sitter_rust.language()` function references the Rust grammar loaded in the Nix shell. The resulting tree allows you to programmatically inspect the structure of the code.
56