Skip to main content

A Python Parser

Project description

Travis CI build status Coverage Status

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:

>>> 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:

>>> 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"



pip install parso


  • 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.


  • Guido van Rossum (@gvanrossum) for creating the parser generator pgen2 (originally used in lib2to3).

  • Salome Schneider for the extremely awesome parso logo.


0.6.1 (2020-02-03)

  • Add parso.normalizer.Issue.end_pos to make it possible to know where an issue ends

0.6.0 (2020-01-26)

  • Dropped Python 2.6/Python 3.3 support

  • del_stmt names are now considered as a definition (for name.is_definition())

  • Bugfixes

0.5.2 (2019-12-15)

  • Add include_setitem to get_definition/is_definition and get_defined_names (#66)

  • Fix named expression error listing (#89, #90)

  • Fix some f-string tokenizer issues (#93)

0.5.1 (2019-07-13)

  • Fix: Some unicode identifiers were not correctly tokenized

  • Fix: Line continuations in f-strings are now working

0.5.0 (2019-06-20)

  • Breaking Change comp_for is now called sync_comp_for for all Python versions to be compatible with the Python 3.8 Grammar

  • Added .pyi stubs for a lot of the parso API

  • Small FileIO changes

0.4.0 (2019-04-05)

  • Python 3.8 support

  • FileIO support, it’s now possible to use abstract file IO, support is alpha

0.3.4 (2019-02-13)

  • Fix an f-string tokenizer error

0.3.3 (2019-02-06)

  • Fix async errors in the diff parser

  • A fix in iter_errors

  • This is a very small bugfix release

0.3.2 (2019-01-24)

  • 20+ bugfixes in the diff parser and 3 in the tokenizer

  • A fuzzer for the diff parser, to give confidence that the diff parser is in a good shape.

  • Some bugfixes for f-string

0.3.1 (2018-07-09)

  • Bugfixes in the diff parser and keyword-only arguments

0.3.0 (2018-06-30)

  • Rewrote the pgen2 parser generator.

0.2.1 (2018-05-21)

  • A bugfix for the diff parser.

  • Grammar files can now be loaded from a specific path.

0.2.0 (2018-04-15)

  • f-strings are now parsed as a part of the normal Python grammar. This makes it way easier to deal with them.

0.1.1 (2017-11-05)

  • Fixed a few bugs in the caching layer

  • Added support for Python 3.7

0.1.0 (2017-09-04)

  • Pulling the library out of Jedi. Some APIs will definitely change.

Project details

Download files

Download the file for your platform. If you're not sure which to choose, learn more about installing packages.

Source Distribution

parso-0.6.1.tar.gz (394.6 kB view hashes)

Uploaded Source

Built Distribution

parso-0.6.1-py2.py3-none-any.whl (97.6 kB view hashes)

Uploaded Python 2 Python 3

Supported by

AWS AWS Cloud computing and Security Sponsor Datadog Datadog Monitoring Fastly Fastly CDN Google Google Download Analytics Microsoft Microsoft PSF Sponsor Pingdom Pingdom Monitoring Sentry Sentry Error logging StatusPage StatusPage Status page