Do multiprocessing in python dynamically

Question

I have a python file that I am calling via C#. I provide a various number of arguments, one of which is the function that I want to run. I am using multiprocessing with the daemon flag set to True. I then join() the new process with the main with the optional time limit.

Everything works as I want but I want it to be more dynamic so I don't have to have a giant list of if else if statements to decide which function to call.

So, how can I modify

p = Process(target=dc_906, args=(self.transactionCode, self.givexNum, self.amount, queue))

to use something like what is below, where self.function is the name of the defined function:

p = Process(target=self.function, args=(self.transactionCode, self.givexNum, self.amount, queue))

Full python code:

queue = mp.Queue()

if self.function == 'dc_906':
    p = Process(target=self.dc_906, args=(self.transactionCode, self.givexNum, self.amount, queue))
elif self.function == 'dc_901':
    p = Process(target=self.dc_901, args=(self.transactionCode, self.givexNum, self.amount, queue))
else:
    p = Process(target=self.dc_907, args=(self.transactionCode, self.givexNum, self.amount, queue))

p.daemon = True

p.start()

p.join(2)

if p.is_alive():
    print 'alive'

print queue.get()

size = queue.qsize()

roippi · Accepted Answer · 2014-04-02T21:18:39.550

1

Use getattr to dynamically fetch the bound method given a string that describes it:

p = Process(target=getattr(self, self.function), args=(...)

edited Apr 02 '14 at 21:18

answered Apr 02 '14 at 21:05

roippi

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That special case was typed wrong. I have fixed it, they should have all been the same. – B-M Apr 02 '14 at 21:14
Mmkay, straighforward then. – roippi Apr 02 '14 at 21:18
I am getting an a syntax error, I will screen shot it and post it in my question. – B-M Apr 02 '14 at 21:19
You're missing a comma after `getattr()`. – roippi Apr 02 '14 at 21:21
ha, yeah. Just saw that. – B-M Apr 02 '14 at 21:21

score 1 · Answer 2 · edited May 23 '17 at 12:05

1

Like the response to this question, I think you can simply use the getattr function which will create a function object from the given object and string, like so:

myfunc = getattr(self, self.function)

This means you can remove your if statements and try something like the following:

p = Process(target=getattr(self, self.function), ...)

Don't forget to still keep things comma separated.

edited May 23 '17 at 12:05

Community

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answered Apr 02 '14 at 21:21

jbranchaud

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Do multiprocessing in python dynamically

2 Answers2