mirror of
https://github.com/davidhalter/parso.git
synced 2026-01-11 05:53:32 +08:00
734a4b0e67
This is a very intentional change. Previously form feeds were handled very poorly and sometimes where not counted as indentation. This obviously makes sense. But at the same time indentation is very tricky to deal with (both for editors and parso). Especially in the diff parser this led to a lot of very weird issues. The decision probably makes sense since: 1. Almost nobody uses form feeds in the first place. 2. People that use form feeds like Barry Warsaw often put a newline ater them. (e.g Python's email.__init__) 3. If you write an editor you want to be able to identify a unicode character with a clear line/column. This would not be the case if form feeds were just ignored when counting. Form feeds will still work in Jedi, will not cause parse errors and in general you should be fine using them. It might just cause Jedi to count them as indentation **if** you use it like '\f foo()'. This is however confusing for most editors anyway. It leads to a weird display e.g. in VIM, even if it's perfectly valid code in Python. Since parso is a code analysis parser and not the languages parser I think it's fine to ignore this edge case.
###################################################################
parso - A Python Parser
###################################################################
.. image:: https://travis-ci.org/davidhalter/parso.svg?branch=master
:target: https://travis-ci.org/davidhalter/parso
:alt: Travis CI build status
.. image:: https://coveralls.io/repos/github/davidhalter/parso/badge.svg?branch=master
:target: https://coveralls.io/github/davidhalter/parso?branch=master
:alt: Coverage Status
.. image:: https://raw.githubusercontent.com/davidhalter/parso/master/docs/_static/logo_characters.png
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`/`await` are already used as keywords in Python3.6.
- `from __future__ import print_function` is 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