astor is designed to allow easy manipulation of Python source via the AST.
There are some other similar libraries, but astor focuses on the following areas:
- Round-trip an AST back to Python:
- Modified AST doesn't need linenumbers, ctx, etc. or otherwise
be directly compileable for the round-trip to work.
- Easy to read generated code as, well, code
- Can round-trip two different source trees to compare for functional
differences, using the astor.rtrip tool (for example, after PEP8 edits).
- Dump pretty-printing of AST
- Harder to read than round-tripped code, but more accurate to figure out what
is going on.
- Easier to read than dump from built-in AST module
- Non-recursive treewalk
- Sometimes you want a recursive treewalk (and astor supports that, starting
at any node on the tree), but sometimes you don't need to do that. astor
doesn't require you to explicitly visit sub-nodes unless you want to:
- You can add code that executes before a node's children are visited, and/or
- You can add code that executes after a node's children are visited, and/or
- You can add code that executes and keeps the node's children from being
visited (and optionally visit them yourself via a recursive call)
- Write functions to access the tree based on object names and/or attribute names
- Enjoy easy access to parent node(s) for tree rewriting