Python eval: is it still dangerous if I disable builtins and attribute access?

Question

We all know that eval is dangerous, even if you hide dangerous functions, because you can use Python\'s introspection features to dig down into things and re-extract them. F

Answer 1

I'm going to mention one of the new features of Python 3.6 - f-strings.

They can evaluate expressions,

>>> eval('f"{().__class__.__base__}"', {'__builtins__': None}, {})
""

but the attribute access won't be detected by Python's tokenizer:

0,0-0,0:            ENCODING       'utf-8'        
1,0-1,1:            ERRORTOKEN     "'"            
1,1-1,27:           STRING         'f"{().__class__.__base__}"'
2,0-2,0:            ENDMARKER      ''