safecalc

safecalc.py

def safe_calc(chat):
    import ast
    try:
        tree = ast.parse(chat)
    except SyntaxError:
        return None
    for node in ast.walk(tree):
        for instance in [ast.Call,ast.Exec,ast.Import,ast.ImportFrom,ast.FunctionDef,ast.Lambda,ast.ClassDef]:
            if isinstance(node,instance):
                return None
        if isinstance(node,ast.Attribute):
            if node.attr.startswith('__'):
                return None
        if isinstance(node,ast.Name):
            if node.id.startswith('__'):
                return None
    return eval(chat)