[Tutor] Calling a function by string name

[Smith, Jeff]

Fantastic...that really did the trick!  I actually made one modification
since p4python allows you to run Perforce commands by calling them with
obj.run_COMMAND(args) so the final solution was:
 
    def _p4run(self, method, *args):
        'runs a Perforce command'
        try:
            if callable(method):
                return method(*args)
            elif hasattr(self._client, method) and
callable(getattr(self._client, method)):
                return getattr(self._client, method)(*args)
            elif hasattr(self._client, 'run_'+method) and
callable(getattr(self._client, 'run_'+method)):
                return getattr(self._client, 'run_'+method)(*args)
            elif hasattr(self._client, method): 
                raise TypeError(method) # not callable
            else:
                raise AttributeError(method) # no method/member with
that name
        except p4.P4Client.error:
            raise
        except:
            if self._client.errors:
                raise p4.P4Client.error('\n'.join(self._client.errors))
            else:
                raise

Thanks,
Jeff

-----Original Message-----
From: Michael P. Reilly [mailto:arcege at gmail.com] 
Sent: Friday, July 21, 2006 1:36 PM
To: Smith, Jeff
Cc: tutor at python.org
Subject: Re: [Tutor] Calling a function by string name


On 7/21/06, Smith, Jeff <jsmith at medplus.com> wrote: 


I have an object and I want to call a method that I have constructed the
name for in a string.
 
For example:
str_method = 'myfun'
obj.str_method
 
Of course, this fails.  I know I could probably do this with exec but is
there a better way?
 
For context, the specific application is a wrapper to calling p4python.
Note that the second return (under the else under the try) is where I
want to call 'method' which is the string name of a method valid for
self._client.
 
    def _p4runner(self, method, *args):
        'runs a Perforce command'
        try:
            if callable(method):
                return method(*args)


elif hasattr(self._client, method) and callable(getattr(self._client,
method)):
    return getattr(self._client, method)(*args)
elif hasattr(self._client, method): 
    raise TypeError(method) # not callable
else:
    raise AttributeError(method) # no method/member with that name



            else:
                return self._client.method(*args)
        except p4.P4Client.error:
            raise
        except:
            if self._client.errors:
                raise p4.P4Client.error('\n'.join(self._client.errors))
            else:
                raise

 
Clear as mud?


Crystally murky. 


  -Arcege

-- 
There's so many different worlds,
So many different suns.
And we have just one world,
But we live in different ones. 

-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://mail.python.org/pipermail/tutor/attachments/20060721/87f367b9/attachment.html