AST Unparser

An AST unparser for Python.

This is a forked version of Simon Percivall's original package found at https://github.com/simonpercivall/astunparse. Compared to the original, this fork adds the following:

• Support for the match compund stmt
• Support for type alias and type parameters
• Added JSON and XML dumps of AST, with full round trip compatibility
• Added cmdline programs (entry points) * py2py * pydump * py2xml and xml2py * py2json and json2py * astunparse with subcommands as above * former functionality python -m astunparse is retained
• Construct own AST composed of generic own ASTNode only * No need to know all the internal AST node types * AST node type is in _class attribute ASTNode
• Fix for issues regarding testing #67 and #57 of the original * The full set of library files can be unparsed as of Python 3.12
• Fix for issue #62 of the original
• The dump funciton is retained, but no attempt is made to compare against ast.dump, test_dump.py is removed

This is a factored out version of unparse found in the Python source distribution; under Demo/parser in Python 2 and under Tools/parser in Python 3.

Basic example:

import inspect
import ast
import astunparse

# get back the source code
astunparse.unparse(ast.parse(inspect.getsource(ast)))

# get a pretty-printed dump of the AST
astunparse.dump(ast.parse(inspect.getsource(ast)))

This library is single-source compatible with Python 2.6 through Python 3.5. It is authored by the Python core developers; I have simply merged the Python 2.7 and the Python 3.5 source and test suites, and added a wrapper. This factoring out is to provide a library implementation that supports both versions.

Added to this is a pretty-printing dump utility function.

The test suite both runs specific tests and also roundtrips much of the standard library.

Extensions and Alternatives

Similar projects include:

• codegen
• astor
• astmonkey
• astprint

None of these roundtrip much of the standard library and fail several of the basic tests in the test_unparse test suite.

This library uses mature and core maintained code instead of trying to patch existing libraries. The unparse and the test_unparse modules are under the PSF license.

Extensions include:

• typed-astunparse: extends astunparse to support type annotations.

• Documentation: http://astunparse.rtfd.org.

Features

• unparses Python AST.
• pretty-prints AST.