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parso - A Python Parser
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Parso is a Python parser that supports error recovery and round-trip parsing
for different Python versions (in multiple Python versions). Parso is also able
to list multiple syntax errors in your python file.
Parso has been battle-tested by jedi_. It was pulled out of jedi to be useful
for other projects as well.
Parso consists of a small API to parse Python and analyse the syntax tree.
A simple example:
.. code-block:: python
>>> import parso
>>> module = parso.parse('hello + 1', version="3.6")
>>> expr = module.children[0]
>>> expr
PythonNode(arith_expr, [<Name: hello@1,0>, <Operator: +>, <Number: 1>])
>>> print(expr.get_code())
hello + 1
>>> name = expr.children[0]
>>> name
<Name: hello@1,0>
>>> name.end_pos
(1, 5)
>>> expr.end_pos
(1, 9)
To list multiple issues:
.. code-block:: python
>>> grammar = parso.load_grammar()
>>> module = grammar.parse('foo +\nbar\ncontinue')
>>> error1, error2 = grammar.iter_errors(module)
>>> error1.message
'SyntaxError: invalid syntax'
>>> error2.message
"SyntaxError: 'continue' not properly in loop"
Resources
Testing <https://parso.readthedocs.io/en/latest/docs/development.html#testing>_PyPI <https://pypi.python.org/pypi/parso>_Docs <https://parso.readthedocs.org/en/latest/>_- Uses
semantic versioning <https://semver.org/>_
Installation
pip install parso
Future
- There will be better support for refactoring and comments. Stay tuned.
- There's a WIP PEP8 validator. It's however not in a good shape, yet.
Known Issues
async/awaitare already used as keywords in Python3.6.from __future__ import print_functionis not ignored.
Acknowledgements
- Guido van Rossum (@gvanrossum) for creating the parser generator pgen2
(originally used in lib2to3). Salome Schneider <https://www.crepes-schnaegg.ch/cr%C3%AApes-schn%C3%A4gg/kunst-f%C3%BCrs-cr%C3%AApes-mobil/>_
for the extremely awesome parso logo.
.. _jedi: https://github.com/davidhalter/jedi