Why 'open' is not a function according to inspect module?

[Ian Kelly]

On Tue, Jun 22, 2010 at 9:42 AM, Peng Yu <pengyu.ut at gmail.com> wrote:
> Hi,
>
> 'open' is not a function according to inspect module. But according to
> help(open), it is a function. Is there something wrong with inspect
> module?
>
> $ cat main.py
> #!/usr/bin/env python
>
> import inspect
>
> def hello():
>  print "Hello World!"
>  return
>
> print inspect.isfunction(str)
> print inspect.isfunction(open)
> print inspect.isfunction(hello)

inspect.isfunction returns True if the object is a *user-defined*
function.  For built-in functions, use inspect.isbuiltin.  You might
also be interested in the callable() function, which returns True if
the object is any object that can be called.

Cheers,
Ian