Metadata-Version: 2.0
Name: asttokens
Version: 1.0.0
Summary: Annotate AST trees with source code positions
Home-page: https://github.com/gristlabs/asttokens
Author: Dmitry Sagalovskiy, Grist Labs
Author-email: dmitry@getgrist.com
License: Apache 2.0
Keywords: code ast parse tokenize refactor
Platform: UNKNOWN
Classifier: Development Status :: 4 - Beta
Classifier: Intended Audience :: Developers
Classifier: Topic :: Software Development :: Libraries :: Python Modules 
Classifier: Topic :: Software Development :: Code Generators
Classifier: Topic :: Software Development :: Compilers
Classifier: Topic :: Software Development :: Interpreters
Classifier: Topic :: Software Development :: Pre-processors
Classifier: Environment :: Console
Classifier: Operating System :: OS Independent
Classifier: Programming Language :: Python :: 2
Classifier: Programming Language :: Python :: 2.7
Classifier: Programming Language :: Python :: 3
Classifier: Programming Language :: Python :: 3.5
Classifier: Programming Language :: Python :: Implementation :: CPython
Requires-Dist: six
Provides-Extra: test
Requires-Dist: astroid; extra == 'test'
Requires-Dist: coverage; extra == 'test'
Requires-Dist: nose; extra == 'test'

ASTTokens
=========

The ``asttokens`` module annotates Python abstract syntax trees (ASTs) with the positions of tokens
and text in the source code that generated them.

It makes it possible for tools that work with logical AST nodes to find the particular text that
resulted in those nodes, for example for automated refactoring or highlighting.

Installation
------------
asttokens is available on PyPI: https://pypi.python.org/pypi/asttokens/::

    pip install asttokens

The code is available on GitHub: https://github.com/gristlabs/asttokens.

Usage
-----
``asttokens`` work with both Python2 and Python3. Here's an example:

.. code-block:: python

    import asttokens, ast
    source = "Robot('blue').walk(steps=10*n)"
    atok = asttokens.ASTTokens(source)
    tree = ast.parse(source)
    atok.mark_tokens(tree)

Once the tree has been marked, nodes get ``.first_token``, ``.last_token`` attributes, and
the ``ASTTokens`` object offers helpful methods:

.. code-block:: python

    attr_node = next(n for n in ast.walk(tree) if isinstance(n, ast.Attribute), None)
    print(atok.get_text(attr_node))
    start, end = attr_node.last_token.startpos, attr_node.last_token.endpos
    print(atok.text[:start] + 'RUN' + atok.text[end:])

Which produces this output:

.. code-block::

    Robot('blue').walk
    Robot('blue').RUN(steps=10*n)

The ``ASTTokens`` object also offers methods to walk and search the list of tokens that make up
the code (or a particular AST node), which is more useful and powerful than dealing with the text
directly.


Tests
-----
Tests are in the ``tests/`` subdirectory. To run all tests, run::

    nosetests


