Function eval_node

IPython/core/guarded_eval.py:765–1190

Evaluate AST node in provided context. Applies evaluation restrictions defined in the context. Currently does not support evaluation of functions with keyword arguments. Does not evaluate actions that always have side effects: - class definitions (``class sth: ...``) - function de

(node: Union[ast.AST, None], context: EvaluationContext)

def eval_node(node: Union[ast.AST, None], context: EvaluationContext):
    """Evaluate AST node in provided context.

    Applies evaluation restrictions defined in the context. Currently does not support evaluation of functions with keyword arguments.

    Does not evaluate actions that always have side effects:

    - class definitions (``class sth: ...``)
    - function definitions (``def sth: ...``)
    - variable assignments (``x = 1``)
    - augmented assignments (``x += 1``)
    - deletions (``del x``)

    Does not evaluate operations which do not return values:

    - assertions (``assert x``)
    - pass (``pass``)
    - imports (``import x``)
    - control flow:

        - conditionals (``if x:``) except for ternary IfExp (``a if x else b``)
        - loops (``for`` and ``while``)
        - exception handling

    The purpose of this function is to guard against unwanted side-effects;
    it does not give guarantees on protection from malicious code execution.
    """
    policy = get_policy(context)

    if node is None:
        return None
    if isinstance(node, (ast.Interactive, ast.Module)):
        result = None
        for child_node in node.body:
            result = eval_node(child_node, context)
        return result
    if isinstance(node, (ast.FunctionDef, ast.AsyncFunctionDef)):
        is_async = isinstance(node, ast.AsyncFunctionDef)
        func_locals = context.transient_locals.copy()
        func_context = context.replace(transient_locals=func_locals)
        is_property = False
        is_static = False
        is_classmethod = False
        for decorator_node in node.decorator_list:
            try:
                decorator = eval_node(decorator_node, context)
            except NameError:
                # if the decorator is not yet defined this is fine
                # especialy because we don't handle imports yet
                continue
            if decorator is property:
                is_property = True
            elif decorator is staticmethod:
                is_static = True
            elif decorator is classmethod:
                is_classmethod = True

        if func_context.class_transients is not None: