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.
asttokens is available on PyPI: https://pypi.python.org/pypi/asttokens/:
pip install asttokens
The code is on GitHub: https://github.com/gristlabs/asttokens.
The API Reference is here: http://asttokens.readthedocs.io/en/latest/api-index.html.
ASTTokens works with both Python2 and Python3.
Here's an example:
import asttokens, ast source = "Robot('blue').walk(steps=10*n)" atok = asttokens.ASTTokens(source, parse=True)
Once the tree has been marked, nodes get
.last_token attributes, and
ASTTokens object offers helpful methods:
attr_node = next(n for n in ast.walk(atok.tree) if isinstance(n, ast.Attribute)) 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:
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
Fork this repository, and clone your fork.
Install the package with test dependencies (ideally in a virtualenv) with:
pip install -e '.[test]'
Run tests in your current interpreter with the command
python -m pytest.
Run tests across all supported interpreters with the
toxcommand. You will need to have the interpreters installed separately. We recommend
pyenvfor that. Use
tox -p autoto run the tests in parallel.
By default certain tests which take a very long time to run are skipped, but they are run on travis CI. To run them locally, set the environment variable
ASTTOKENS_SLOW_TESTS. For example run
ASTTOKENS_SLOW_TESTS=1 toxto run the full suite of tests.