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Welcoming Winter with Python – PyKids and PyLadies

✇Shrini
tshrinivasan

Winter Break for kids

In Canada, we have around 15 days of winter break for all school kids, covering Christmas and New year.

These celebrations are helping much to come out of the winter worries.

Winter is scary word, but people have to go through it, as life has to go on. As we can not travel much and there are no outdoor events/games, we have to be at home, all the days, weeks and months. Organizing indoor events are costly.

To spend the winter actively, many celebrations days are occurring. Halloween, Christmas, Boxing day, New year, Valentine day and more are there, to make the winter active.

Keeping the kids at home for 17 days winter break is tough. We have to engage them whole day. In our apartment, we are conducting many kids events like weekly chess hour, dance hours, board games day, movie time, sleep over nights etc.

Computer Literacy is good here. Kids are learning to use computer at school, from Grade 3 itself. They play many educational games at school. Homework are done with google slides and google docs, from grade 5. Scratch programming also trained here at grade 5. So, they know very well to use computer, read text online, search the internet and gather some info etc.

PyKids

This time, thought of having some tech events for kids. Called for 10 days training as “PyKids”, for grade 5 and above. The announcement was welcomed well by many parents. We had around 17 kids participated.

As our house is empty mostly, ( thanks to Nithya, for the minimalistic life style ), our hall helped for gathering and teaching.

By keeping the hall empty, we are using the place as Daily Zumba dance hall, mini party hall, DJ hall, kids play area and now as a learning place.

Teaching Python for kids is not easy. The kids are not ready to listen to any long talks. They can not even listen to my regular “python introduction” slides. So, jumped into hands-on on the day one itself.

My mentor, Asokan Pichai explained how we have to goto hands-on on any python training, few months ago. Experienced the benefits of it this time.

Even-though, I am using Python for 10+ years, teaching it to kids was really tough. I had to read few books and read on more basics, so that I can explain the building blocks of python with more relevant examples for kids.

The kids are good at asking questions. They share feedback with their eyes itself. It is a huge different on teaching to adults. Most of the adults don’t ask questions. They hesitate to say they don’t understand something. But, kids are brave enough to ask questions and express the feedback immediately.

With a training on 4-6 pm everyday, for around 10 days, we can cover so little of python only.

We practiced the code here – https://github.com/tshrinivasan/python-for-kids We used https://www.online-python.com/ as IDE, as the kids have laptops and tablets with different OS. Will install Python on their laptops on next events so that they can explore more python libraries.

On the final day, my friend Jay Varadharajan, gave a Pizza party for all kids, along with a participation certificate.

Thanks for all the questions kids. Along with you, I learnt a lot. Thanks for all the parents for the great support.

PyLadies

Nithya wanted to try out full day training for her friends. Getting a time of 9-5 to learn something is so luxury for many people. Still, around 10 friends participated.

Nithya took the day with all hands-on. She covered the variables, getting input, if/else, for/while loop, string/list operations. The participants were happy to dive into programming so quickly.

“A byte of Python” is a super easy book to learn python. Read it here for free. https://python.swaroopch.com/

Gave this link as asked to read/practice regularly. Hope they are following the book.

Hall for PyLadies meetup

Home as Learning Space

Thus, we are converting our home as a learning space for kids and friends. Thinking of conducting some technical meetups too. ( I am missing all the Linux Users groups meetings and hackathons). Hope we can get more tech events in the winter and make it so interesting and productive.

Welcoming Winter with Python – PyKids and PyLadies

✇Shrini
tshrinivasan

Winter Break for kids

In Canada, we have around 15 days of winter break for all school kids, covering Christmas and New year.

These celebrations are helping much to come out of the winter worries.

Winter is scary word, but people have to go through it, as life has to go on. As we can not travel much and there are no outdoor events/games, we have to be at home, all the days, weeks and months. Organizing indoor events are costly.

To spend the winter actively, many celebrations days are occurring. Halloween, Christmas, Boxing day, New year, Valentine day and more are there, to make the winter active.

Keeping the kids at home for 17 days winter break is tough. We have to engage them whole day. In our apartment, we are conducting many kids events like weekly chess hour, dance hours, board games day, movie time, sleep over nights etc.

Computer Literacy is good here. Kids are learning to use computer at school, from Grade 3 itself. They play many educational games at school. Homework are done with google slides and google docs, from grade 5. Scratch programming also trained here at grade 5. So, they know very well to use computer, read text online, search the internet and gather some info etc.

PyKids

This time, thought of having some tech events for kids. Called for 10 days training as “PyKids”, for grade 5 and above. The announcement was welcomed well by many parents. We had around 17 kids participated.

As our house is empty mostly, ( thanks to Nithya, for the minimalistic life style ), our hall helped for gathering and teaching.

By keeping the hall empty, we are using the place as Daily Zumba dance hall, mini party hall, DJ hall, kids play area and now as a learning place.

Teaching Python for kids is not easy. The kids are not ready to listen to any long talks. They can not even listen to my regular “python introduction” slides. So, jumped into hands-on on the day one itself.

My mentor, Asokan Pichai explained how we have to goto hands-on on any python training, few months ago. Experienced the benefits of it this time.

Even-though, I am using Python for 10+ years, teaching it to kids was really tough. I had to read few books and read on more basics, so that I can explain the building blocks of python with more relevant examples for kids.

The kids are good at asking questions. They share feedback with their eyes itself. It is a huge different on teaching to adults. Most of the adults don’t ask questions. They hesitate to say they don’t understand something. But, kids are brave enough to ask questions and express the feedback immediately.

With a training on 4-6 pm everyday, for around 10 days, we can cover so little of python only.

We practiced the code here – https://github.com/tshrinivasan/python-for-kids We used https://www.online-python.com/ as IDE, as the kids have laptops and tablets with different OS. Will install Python on their laptops on next events so that they can explore more python libraries.

On the final day, my friend Jay Varadharajan, gave a Pizza party for all kids, along with a participation certificate.

Thanks for all the questions kids. Along with you, I learnt a lot. Thanks for all the parents for the great support.

PyLadies

Nithya wanted to try out full day training for her friends. Getting a time of 9-5 to learn something is so luxury for many people. Still, around 10 friends participated.

Nithya took the day with all hands-on. She covered the variables, getting input, if/else, for/while loop, string/list operations. The participants were happy to dive into programming so quickly.

“A byte of Python” is a super easy book to learn python. Read it here for free. https://python.swaroopch.com/

Gave this link as asked to read/practice regularly. Hope they are following the book.

Hall for PyLadies meetup

Home as Learning Space

Thus, we are converting our home as a learning space for kids and friends. Thinking of conducting some technical meetups too. ( I am missing all the Linux Users groups meetings and hackathons). Hope we can get more tech events in the winter and make it so interesting and productive.

Learning Notes #10 – Lazy Queues | RabbitMQ

✇Parotta Salna
Mr.ParottaSalna

What Are Lazy Queues?

  • Lazy Queues are designed to store messages primarily on disk rather than in memory.
  • They are optimized for use cases involving large message backlogs where minimizing memory usage is critical.

Key Characteristics

  1. Disk-Based Storage – Messages are stored on disk immediately upon arrival, rather than being held in memory.
  2. Low Memory Usage – Only minimal metadata for messages is kept in memory.
  3. Scalability – Can handle millions of messages without consuming significant memory.
  4. Message Retrieval – Retrieving messages is slower because messages are fetched from disk.
  5. Durability – Messages persist on disk, reducing the risk of data loss during RabbitMQ restarts.

Trade-offs

  • Latency: Fetching messages from disk is slower than retrieving them from memory.
  • Throughput: Not suitable for high-throughput, low-latency applications.

Choose Lazy Queues if

  • You need to handle very large backlogs of messages.
  • Memory is a constraint in your system.Latency and throughput are less critical.

Implementation

Pre-requisites

1. Install and run RabbitMQ on your local machine. 


docker run -it --rm --name rabbitmq -p 5672:5672 -p 15672:15672 rabbitmq:4.0-management

2. Install the pika library


pip install pika

Producer (producer.py)

This script sends a persistent message to a Lazy Queue.

import pika

# RabbitMQ connection parameters for localhost
connection_params = pika.ConnectionParameters(host="localhost")

# Connect to RabbitMQ
connection = pika.BlockingConnection(connection_params)
channel = connection.channel()

# Custom Exchange and Routing Key
exchange_name = "custom_exchange"
routing_key = "custom_routing_key"
queue_name = "lazy_queue_example"

# Declare the custom exchange
channel.exchange_declare(
    exchange=exchange_name,
    exchange_type="direct",  # Direct exchange routes messages based on the routing key
    durable=True
)

# Declare a Lazy Queue
channel.queue_declare(
    queue=queue_name,
    durable=True,
    arguments={"x-queue-mode": "lazy"}  # Configure the queue as lazy
)

# Bind the queue to the custom exchange with the routing key
channel.queue_bind(
    exchange=exchange_name,
    queue=queue_name,
    routing_key=routing_key
)

# Publish a message
message = "Hello from the Producer via Custom Exchange!"
channel.basic_publish(
    exchange=exchange_name,
    routing_key=routing_key,
    body=message,
    properties=pika.BasicProperties(delivery_mode=2)  # Persistent message
)

print(f"Message sent to Lazy Queue via Exchange: {message}")

# Close the connection
connection.close()

Consumer (consumer.py)

import pika

# RabbitMQ connection parameters for localhost
connection_params = pika.ConnectionParameters(host="localhost")

# Connect to RabbitMQ
connection = pika.BlockingConnection(connection_params)
channel = connection.channel()

# Custom Exchange and Routing Key
exchange_name = "custom_exchange"
routing_key = "custom_routing_key"
queue_name = "lazy_queue_example"

# Declare the custom exchange
channel.exchange_declare(
    exchange=exchange_name,
    exchange_type="direct",  # Direct exchange routes messages based on the routing key
    durable=True
)

# Declare the Lazy Queue
channel.queue_declare(
    queue=queue_name,
    durable=True,
    arguments={"x-queue-mode": "lazy"}  # Configure the queue as lazy
)

# Bind the queue to the custom exchange with the routing key
channel.queue_bind(
    exchange=exchange_name,
    queue=queue_name,
    routing_key=routing_key
)

# Callback function to process messages
def callback(ch, method, properties, body):
    print(f"Received message: {body.decode()}")
    ch.basic_ack(delivery_tag=method.delivery_tag)  # Acknowledge the message

# Start consuming messages
channel.basic_consume(queue=queue_name, on_message_callback=callback, auto_ack=False)

print("Waiting for messages. To exit, press CTRL+C")
try:
    channel.start_consuming()
except KeyboardInterrupt:
    print("Stopped consuming.")

# Close the connection
connection.close()

Explanation

  1. Producer
    • Defines a custom exchange (custom_exchange) of type direct.
    • Declares a Lazy Queue (lazy_queue_example).
    • Binds the queue to the exchange using a routing key (custom_routing_key).
    • Publishes a persistent message via the custom exchange and routing key.
  2. Consumer
    • Declares the same exchange and Lazy Queue to ensure they exist.
    • Consumes messages routed to the queue through the custom exchange and routing key.
  3. Custom Exchange and Binding
    • The direct exchange type routes messages based on an exact match of the routing key.
    • Binding ensures the queue receives messages published to the exchange with the specified key.
  4. Lazy Queue Behavior
    • Messages are stored directly on disk to minimize memory usage.

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