Use a function object: class Copier(object): def __init__(self, tgtdir): self.target_dir = tgtdir def __call__(self, src): copy_file(src, self.target_dir) To run your Pool.map: p.map(Copier(target_dir), file_list)
You can use functools.partial for this (as you suspected): from functools import partial def target(lock, iterable_item): for item in iterable_item: # Do cool stuff if (… some condition here …): lock.acquire() # Write to stdout or logfile, etc. lock.release() def main(): iterable = [1, 2, 3, 4, 5] pool = multiprocessing.Pool() l = multiprocessing.Lock() func … Read more
The problem is in this line: with pattern.findall(row) as f: You are using the with statement. It requires an object with __enter__ and __exit__ methods. But pattern.findall returns a list, with tries to store the __exit__ method, but it can’t find it, and raises an error. Just use f = pattern.findall(row) instead.
The multiprocessing.pool.Pool class creates the worker processes in its __init__ method, makes them daemonic and starts them, and it is not possible to re-set their daemon attribute to False before they are started (and afterwards it’s not allowed anymore). But you can create your own sub-class of multiprocesing.pool.Pool (multiprocessing.Pool is just a wrapper function) and … Read more
The problem is that multiprocessing must pickle things to sling them among processes, and bound methods are not picklable. The workaround (whether you consider it “easy” or not;-) is to add the infrastructure to your program to allow such methods to be pickled, registering it with the copy_reg standard library method. For example, Steven Bethard’s … Read more
This is a Python bug. When waiting for a condition in threading.Condition.wait(), KeyboardInterrupt is never sent. Repro: import threading cond = threading.Condition(threading.Lock()) cond.acquire() cond.wait(None) print “done” The KeyboardInterrupt exception won’t be delivered until wait() returns, and it never returns, so the interrupt never happens. KeyboardInterrupt should almost certainly interrupt a condition wait. Note that this … Read more
Heap memory The heap memory is the runtime data area from which the Java VM allocates memory for all class instances and arrays. The heap may be of a fixed or variable size. The garbage collector is an automatic memory management system that reclaims heap memory for objects. Eden Space: The pool from which memory … Read more