calling a function from string

[Dustan]

On Oct 22, 4:41 am, "Francesco Guerrieri" <f.guerri... at gmail.com>
wrote:
> On 10/22/07, james_027 <cai.hai... at gmail.com> wrote:
>
> > hi,
>
> > i have a function that I could like to call, but to make it more
> > dynamic I am constructing a string first that could equivalent to the
> > name of the function I wish to call. how could I do that? the string
> > could might include name of the module.
>
> > for example
>
> > a_string = 'datetime.' + 'today()'
>
> > how could I call a_string as function?
>
> you could use getattr:
>
> function_name = 'time'  # this is a string
> module_name = 'time'   # this is a string, too
>
> my_function = getattr(module_name, function_name) # this is the
> function object,
> # equivalent to my_function = time.time


Not quite.

============================================
>>> function_name = 'time'  # this is a string
>>> module_name = 'time'   # this is a string, too
>>> my_function = getattr(module_name, function_name)
Traceback (most recent call last):
  File "<pyshell#3>", line 1, in <module>
    my_function = getattr(module_name, function_name)
AttributeError: 'str' object has no attribute 'time'
============================================

It's actually equivalent to:

============================================
>>> "time".time
Traceback (most recent call last):
  File "<pyshell#0>", line 1, in <module>
    "time".time
AttributeError: 'str' object has no attribute 'time'
============================================