Python - test whether object is a builtin function

Question

Is there a nice way to check whether object o is a builtin Python function?

I know I can use, for example

type(o) == type(pow)

beca

Answer 1

you can also do

import __builtin__
o in __builtin__.__dict__.values()

or, in CPython:

o in __builtins__.__dict__.values()

but note that you rely on an implementation detail here.

---

>>> pow in __builtins__.__dict__.values()
True
>>> def a():
...   pass
...
>>> a in __builtins__.__dict__.values()
False
>>>