import queue
# Create a bounded queue with a maximum size of 5
q = queue.Queue(maxsize=5)
# Put items in the queue
for i in range(5):
q.put(i)
# Check if the queue is full
print(f"Is the queue full? {q.full()}")
✅ Fix:queue.Queue() creates a bounded queue with a specified maxsize.
🔹 2. Using queue.Queue in a Producer-Consumer Example
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import queue
import threading
import time
# Create a bounded queue
q = queue.Queue(maxsize=5)
def producer():
for i in range(10):
q.put(i)
print(f"Produced: {i}")
time.sleep(0.5)
def consumer():
while True:
item = q.get()
print(f"Consumed: {item}")
time.sleep(1)
# Create threads
producer_thread = threading.Thread(target=producer)
consumer_thread = threading.Thread(target=consumer)
producer_thread.start()
consumer_thread.start()
producer_thread.join()
consumer_thread.join()
✅ Fix: The producer adds items to the queue, and the consumer takes items out. The queue's bounded size prevents the producer from overwhelming the consumer.
🔹 3. Blocking Behavior on Full Queue
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✅ Fix: When the queue reaches its max size, the producer will be blocked until the consumer processes an item.
🔹 4. Using queue.Queue for Task Scheduling
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✅ Fix: Tasks are queued and processed by worker threads. The queue's bounded nature ensures limited concurrent processing.
🔹 5. Handling Timeouts with Bounded Queues
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✅ Fix: The timeout parameter allows the producer to timeout and handle cases when the queue is full.
🔹 6. Thread-Safe Queue with queue.Queue
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✅ Fix: Multiple threads produce items safely with a thread-safe queue.
🔹 7. Using queue.PriorityQueue for Task Prioritization
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✅ Fix:PriorityQueue allows tasks to be prioritized by a tuple of priority and task data.
🔹 8. Bounded Queue with queue.LifoQueue (Stack-like Behavior)
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✅ Fix:LifoQueue implements a stack (Last In, First Out) for the queue behavior.
🔹 9. Gracefully Closing Threads with queue.Queue
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✅ Fix: Use None as a sentinel value to signal the consumer to stop processing.
🔹 10. Using queue.Queue for Rate Limiting
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✅ Fix: A rate limit is imposed by the bounded queue's size, limiting the number of items produced in a fixed amount of time.
import queue
import threading
import time
q = queue.Queue(maxsize=3)
def producer():
for i in range(5):
print(f"Attempting to produce: {i}")
q.put(i)
print(f"Produced: {i}")
time.sleep(1)
def consumer():
while True:
item = q.get()
print(f"Consumed: {item}")
time.sleep(2)
producer_thread = threading.Thread(target=producer)
consumer_thread = threading.Thread(target=consumer)
producer_thread.start()
consumer_thread.start()
producer_thread.join()
consumer_thread.join()
import queue
import threading
q = queue.Queue(maxsize=10)
def task_worker():
while True:
task = q.get()
print(f"Task {task} is being processed")
q.task_done()
# Start multiple worker threads
for i in range(3):
t = threading.Thread(target=task_worker)
t.daemon = True
t.start()
# Add tasks to the queue
for task in range(20):
q.put(task)
q.join() # Wait for all tasks to be processed
import queue
import threading
import time
q = queue.Queue(maxsize=2)
def producer():
try:
q.put(1, timeout=1) # Timeout if the queue is full
print("Produced: 1")
except queue.Full:
print("Queue is full, producer is waiting...")
producer_thread = threading.Thread(target=producer)
producer_thread.start()
producer_thread.join()
import queue
import threading
q = queue.Queue(maxsize=5)
def thread_function():
for i in range(5):
q.put(i)
print(f"Thread {threading.current_thread().name} produced: {i}")
# Create multiple threads
threads = [threading.Thread(target=thread_function) for _ in range(3)]
for thread in threads:
thread.start()
for thread in threads:
thread.join()
# Check the queue's final state
print(f"Queue size: {q.qsize()}")
import queue
import threading
import time
pq = queue.PriorityQueue(maxsize=5)
def producer():
for i in range(5, 0, -1):
pq.put((i, f"task-{i}"))
print(f"Produced: task-{i}")
time.sleep(0.5)
def consumer():
while True:
priority, task = pq.get()
print(f"Consumed: {task} with priority {priority}")
pq.task_done()
time.sleep(1)
producer_thread = threading.Thread(target=producer)
consumer_thread = threading.Thread(target=consumer)
producer_thread.start()
consumer_thread.start()
producer_thread.join()
consumer_thread.join()
import queue
import threading
import time
q = queue.LifoQueue(maxsize=3)
def producer():
for i in range(5):
q.put(i)
print(f"Produced: {i}")
time.sleep(0.5)
def consumer():
while True:
item = q.get()
print(f"Consumed: {item}")
time.sleep(1)
producer_thread = threading.Thread(target=producer)
consumer_thread = threading.Thread(target=consumer)
producer_thread.start()
consumer_thread.start()
producer_thread.join()
consumer_thread.join()
import queue
import threading
import time
q = queue.Queue(maxsize=5)
def producer():
for i in range(5):
q.put(i)
print(f"Produced: {i}")
time.sleep(1)
def consumer():
while True:
item = q.get()
if item is None: # Signal to stop
break
print(f"Consumed: {item}")
time.sleep(1)
producer_thread = threading.Thread(target=producer)
consumer_thread = threading.Thread(target=consumer)
producer_thread.start()
consumer_thread.start()
producer_thread.join()
q.put(None) # Signal the consumer to stop
consumer_thread.join()
import queue
import threading
import time
q = queue.Queue(maxsize=3)
def producer():
for i in range(6):
if q.full():
print(f"Rate limit reached, producer waiting...")
q.put(i)
print(f"Produced: {i}")
time.sleep(1)
producer_thread = threading.Thread(target=producer)
producer_thread.start()
producer_thread.join()