google-pasta

pasta: Python AST Augmentation

This is still a work-in-progress; there is much more to do. Existing functionality may not be perfect.

Mission

Enable python source code refactoring through AST modifications.

Sample use cases:

• Facilitate moving or renaming python modules by rewriting import statements.
• Refactor code to enforce a certain style, such as reordering function definitions.
• Safely migrate code from one API to another.

Design Goals

• Symmetry: Given any input source, it should hold that pasta.dump(pasta.parse(src)) == src.
• Mutability: Any changes made in the AST are reflected in the code generated from it.
• Standardization: The syntax tree parsed by pasta will not introduce new nodes or structure that the user must learn.

Python Version Support

Supports python 2.7 and up to 3.8.

Dependencies

pasta depends on six.

Basic Usage

import pasta
tree = pasta.parse(source_code)

# ... Augment contents of tree ...

source_code = pasta.dump(tree)

Built-in Augmentations

Pasta includes some common augmentations out-of-the-box. These can be used...