Python recursion,memorization,decorator memorization

Python recursion example1

Python recursion with memorization

Python recursion with memorization with python decorator

Python data structures list,dic,set,counter etc.. explained in malayalam

I tried to explain some of the python built in data structures in Malayalam here.

Python example for list

Python example for dictionary

Python example for Set

Python example for Counter

Python example for defaultdictonary

Traverse through 2 dimensional list

A list is a data structure that holds an ordered collection of items i.e. you can store a sequence of items in a list
Slicing the list and manipulating the list is easy in python. Since its a sequence is iterable, we can use for loop on list. "Sequence in Python, sequence is the generic term for an ordered set.Lists are the most versatile sequence type. The elements of a list can be any object, and lists are mutable - they can be changed. Elements can be reassigned or removed, and new elements can be inserted" python two dimensional list

Python TRIE

Python implementation for TRIE


TRIE is very interesting data structure and its very much used in word suggestion algorithms. Python implementation for this would easiest way to learn it.



Python Trie example 1

Python Generator

Have you ever  think through how to build an function that generate infinite series ?
You might be  thinking why can't we use an infinite loop! the problem is you can't come of the loop and again resume from the position/state where you stopped .

But generators helps in this case, they are just like functions but the difference is they have yield keyword in the definition which is like a return wrapped with generator-iterator object

"When you call either a function or a generator, a stackframe is created. It has the local variables
(including the arguments passed into the function),a code pointer to the active opcode, and a stack for pending try-blocks,with-blocks, or loops.

In a regular function, execution begins immediately.When return is encountered, the final result is kept and the stackframe is freed along with everything it referenced.

In a generator function, the stackframe is wrapped in a generator-iterator object and returned immediately. The code in the generator function only runs when called by next(g) or g.send(v). Execution is suspended when yield is encountered. "



Python generator infinite sequence example

Python generator things to be known ( exhausted generator )

Python inheritance - Examples

Python inheritance explained with Visualization

Python inheritance example 1

Python inheritance ( with child methods) example 2

Python inheritance and overriding example3

How to deploy python programs to Docker

Running python programs in Docker

It is quite easy to run your python programs in docker. For getting started with python in docker, we need to install docker in our system.

I am using Ubuntu and followed the instruction details beginners commands to start with Docker.

Once you have installed docker, we can start building our docker. We can create a separate folder/directory for this in our system.

FROM tells Docker which image you base your image on (in the example, Python 3).

RUN tells Docker which additional commands to execute.

CMD tells Docker to execute the command when the image loads.

Dockerfile:

#base image
FROM python:3

#adding our first program/application to docker image
ADD app.py /
ADD app2.py /

#this time we are using a script to run our applications.
ADD script.sh /
#make the script executable
RUN ["chmod", "+x", "./script.sh"]
#changed the command to run the script
CMD ./script.sh 
#you can read more about commands in docker at https://docs.docker.com
#add the command instruction
#CMD ["python","./app.py"]

script file:

You can specify your python programs in the script.
Note: I have explicitly used python3 to run the programs.

#!bin/bash

#first process
python3 app.py

#second process
python3 app2.py

Python applications

print("this is my first pythong docker program")