Advanced AST validation

pip install astvalidate==2021.12.31



A series of AST validators for validating the integrity of the given abstract syntax tree.


validate(tree: ast.Module, level: Optional[Literal[1, 2, 3]] = None) -> bool

tree is the AST object that you want to verify. level is an argument to pass the level of strictness, and turn on/off some of the validators. For a detailed list of validators, see the table below:

Validator Level Description
Syntatical 1 Emulates syntax warnings that are normally generated by compiler.
Simple 1 Does simple verifications, similar to PyAST_Validate interface
Symbolic 2 Emulates syntax error that are normally generated by symbol table
Contextual 3 Ensures everything is in the right context.

If there are any errors, validate() will raise a SyntaxError or issue SyntaxWarnings on the location of the target node.

import ast
import astvalidate

tree = ast.parse("""
def func():
    raise ValueError from something
tree.body[0].body[0].exc = None
assert astvalidate.validate(tree)
File "<string>", line 3
SyntaxError: Raise's cause can't be used without setting an exception