dynamic func. call

[Aljosa Mohorovic]

can i do something like this:

s = "myFunction "
a = s() # equals to: a = myFunction()

[Ola Natvig]

Re: dynamic func. call

Aljosa Mohorovic wrote:[color=blue]
> can i do something like this:
>
> s = "myFunction "
> a = s() # equals to: a = myFunction()
>
>[/color]

a = locals()[x]()

locals() returns a dictionary with string keys that you can use

--
--------------------------------------
Ola Natvig <ola.natvig@inf osense.no>
infoSense AS / development

[Tim Jarman]

Re: dynamic func. call

Aljosa Mohorovic wrote:
[color=blue]
> can i do something like this:
>
> s = "myFunction "
> a = s() # equals to: a = myFunction()[/color]

Functions are first-class objects in Python, so you can do:

def myFunction():
# whatever

which creates a function object and binds the name myFunction to it. Then:

s = myFunction

just binds the name s to your function object, and therefore:

a = s()

is the same as:

a = myFunction()


--
Website: www DOT jarmania FULLSTOP com

[ajikoe@gmail.com]

Re: dynamic func. call

Try this:

def myfunc():
print "helo"

s = "myfunc()"
a = eval(s)

[Duncan Booth]

Re: dynamic func. call

ajikoe@gmail.co m wrote:
[color=blue]
> Try this:
>
> def myfunc():
> print "helo"
>
> s = "myfunc()"
> a = eval(s)
>[/color]

No, please don't try that. Good uses for eval are *very* rare, and this
isn't one of them.

Use the 'a = locals()[x]()' suggestion (or vars() instead of locals()), or
even better put all the functions callable by this method into a class and
use getattr() on an instance of the class.

A Pythonic way to do this sort of thing is to put all the functions that
are callable indirectly into a class and give them names which contain a
prefix to make it obvious that they are callable in this way and then add
the prefix onto the string:

class C:
def command_myfunc( self):
return 42

def default_command (self):
raise NotImplementedE rror('Unknown command')

def execute(self, s):
return getattr(self, 'command_'+s, self.default_co mmand)()

commands = C()
print commands.execut e('myfunc')

That way you can be quickly tell which functions can be called indirectly
and which can't; you can control what happens when no suitable function
exists; and you can easily extend the functionality by subclassing your
base class.