astvalidate 2021.12.31

Advanced AST validation

astvalidate

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

API

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