the.
```
import inspect
inspect.isfunction
```
does not consider a
```
builtin_function_or_method
```
as a function.
for example,
```
inspect.isfunction(abs)
```
gives,
```
False
```
in the background even the builtin `abs` is a function, so shouldn't it return True?

the way this check is implemented is by matching the type of a builtin_function_or_method with,
```
type(len)
```
and since, `type(len)` is `builtin_function_or_method`, so, the `inspect.isfunction` check gives False.
But in my opinion, it should return True, even for builtin functions or methods.