initial creation

py3interm/EXAMPLES/multi_processing.py

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+#!/usr/bin/env python
+import sys
+import random
+from multiprocessing import Manager, Lock, Process, Queue, freeze_support
+from queue import Empty
+import time
+
+NUM_ITEMS = 25000  # <1>
+POOL_SIZE = 100
+
+
+class RandomWord():  # <2>
+    def __init__(self):
+        with open('../DATA/words.txt') as words_in:
+            self._words = [word.rstrip('\n\r') for word in words_in]
+        self._num_words = len(self._words)
+
+    def __call__(self):  # <3>
+        return self._words[random.randrange(0, self._num_words)]
+
+
+class Worker(Process):  # <4>
+
+    def __init__(self, name, queue, lock, result):  # <5>
+        Process.__init__(self)
+        self.queue = queue
+        self.result = result
+        self.lock = lock
+        self.name = name
+
+    def run(self):  # <6>
+        while True:
+            try:
+                word = self.queue.get(block=False)  # <7>
+                word = word.upper()  # <8>
+                with self.lock:
+                    self.result.append(word)  # <9>
+
+            except Empty:  # <10>
+                break
+
+
+if __name__ == '__main__':
+    if sys.platform == 'win32':
+        freeze_support()
+
+    word_queue = Queue()  # <11>
+
+    manager = Manager()  # <12>
+    shared_result = manager.list()  # <13>
+    result_lock = Lock()  # <14>
+
+    random_word = RandomWord()  # <15>
+    for i in range(NUM_ITEMS):
+        w = random_word()
+        word_queue.put(w)  # <16>
+
+    start_time = time.ctime()
+
+    pool = []  # <17>
+    for i in range(POOL_SIZE):  # <18>
+        worker_name = "Worker {:03d}".format(i)
+        w = Worker(worker_name, word_queue, result_lock, shared_result)  # <19>
+        #
+        w.start()  # <20>
+        pool.append(w)  # <21>
+
+    for t in pool:
+        t.join()  # <22>
+
+    end_time = time.ctime()
+
+    print((shared_result[-50:]))  # <23>
+    print(len(shared_result))
+    print(start_time)
+    print(end_time)