Tree-sitter Python Bindings

Common errors

Warnings

Install

Install compatibility verified last tested: 2026-05-12

Imports

• Language

  from tree_sitter import Language

• Parser

  from tree_sitter import Parser

• Query

  from tree_sitter import Query

• QueryCursor

  from tree_sitter import QueryCursor

• language
  wrong

  from tree_sitter_python import language; PY_LANGUAGE = Language(language())

  correct

  import tree_sitter_python as tspython; PY_LANGUAGE = Language(tspython.language())

  It's best practice to import the language module with an alias and then access its `language()` function to avoid name collisions and for clarity. Direct import of `language` is also common but less explicit.

Quickstart stale last tested: 2026-04-24

This quickstart demonstrates how to load a language grammar (Python in this case), create a parser, parse a code string into a syntax tree, and then use Tree-sitter's query system to find specific patterns within the tree, such as function names. It highlights the typical workflow of initializing a `Language` object from a pre-compiled grammar and then using a `Parser` to process source code. Ensure the relevant language package (e.g., `tree-sitter-python`) is installed alongside `tree-sitter`.

import os
from tree_sitter import Language, Parser

# NOTE: For this to work, you need 'tree-sitter-python' installed
# pip install tree-sitter-python
import tree_sitter_python as tspython

# Load the Python language grammar
PY_LANGUAGE = Language(tspython.language())

# Create a parser and set its language
parser = Parser()
parser.set_language(PY_LANGUAGE)

# Source code to parse
code = b""" 
def greet(name): # type: (str) -> None
    print(f"Hello, {name}!")

greet("World")
"""

# Parse the code
tree = parser.parse(code)

# Get the root node and print its type
root_node = tree.root_node
print(f"Root node type: {root_node.type}")

# Traverse the tree (example: find function definitions)
query_string = """ 
(function_definition
  name: (identifier) @function.name)
"""
query = PY_LANGUAGE.query(query_string)

captures = query.captures(root_node)
for node, name in captures:
    print(f"Found function: {node.text.decode('utf8')} (capture: {name})")