Go through a number of functions in Python

Question

I have an unknown number of functions in my python script (well, it is known, but not constant) that start with site_... I was wondering if there's a way to go through all of these functions in some main function that calls for them. something like:

foreach function_that_has_site_ as coolfunc
   if coolfunc(blabla,yada) == true:
      return coolfunc(blabla,yada)

so it would go through them all until it gets something that's true.

thanks!

Answer 1

Have you tried using the inspect module?

http://docs.python.org/library/inspect.html

The following will return the methods:

inspect.getmembers

Then you could invoke with:

methodobjToInvoke = getattr(classObj, methodName) 
methodobj("arguments") 

Answer 2

Try dir(), globals() or locals(). Or inspect module (as mentioned above).

def site_foo():
  pass

def site_bar():
  pass

for name, f in globals().items():
  if name.startswith("site_"):
    print name, f()

Answer 3

This method goes through all properties of the current module and executes all functions it finds with a name starting with site_:

import sys
import types
for elm in dir():
    f = getattr(sys.modules[__name__], elm)
    if isinstance(f, types.FunctionType) and f.__name__[:5] == "site_":
        f()

The function-type check is unnecessary if only functions are have names starting with site_.

Answer 4

def run():
    for f_name, f in globals().iteritems():
        if not f_name.startswith('site_'):
            continue
        x = f()
        if x:
            return x

Answer 5

The inspect module, already mentioned in other answers, is especially handy because you get to easily filter the names and values of objects you care about. inspect.getmembers takes two arguments: the object whose members you're exploring, and a predicate (a function returning bool) which will accept (return True for) only the objects you care about.

To get "the object that is this module" you need the following well-known idiom:

import sys
this_module = sys.modules[__name__]

In your predicate, you want to select only objects which are functions and have names that start with site_:

import inspect
def function_that_has_site(f):
    return inspect.isfunction(f) and f.__name__.startswith('site_')

With these two items in hand, your loop becomes:

for n, coolfunc in inspect.getmembers(this_module, function_that_has_site):
   result = coolfunc(blabla, yada)
   if result: return result

I have also split the loop body so that each function is called only once (which both saves time and is a safer approach, avoiding possible side effects)... as well as rewording it in Python;-)

Answer 6

It's best to use a decorator to enumerate the functions you care about:

_funcs = []

def enumfunc(func):
  _funcs.append(func)
  return func

@enumfunc
def a():
  print 'foo'

@enumfunc
def b():
  print 'bar'

@enumfunc
def c():
  print 'baz'

if __name__ == '__main__':
  for f in _funcs:
    f()