Functional programming in Python is possible with the use of lambda map reduce and filter functions. This article briefly describe use of each these functions.

Lambda : Lambda specifies an anonymous function. It is used to declare a function with no name; When you want to use function only once. But why would you declare a function if you don’t want to reuse the code? Read on you’ll see. Syntax: lambda arg1, arg2 : expression

lambda x : x*x

This lambda expression with just one argument x which returns square of x.

Map : It takes two arguments, the first argument is name of a function and second argument is a sequence. map() applies function f to all elements in the sequence and returns a new sequence. Syntax: map (func, sequence)

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list = [1, 2, 3]
map (lambda x : x*x, list)

#output: [1, 4, 9]

This code also demonstrates use of lambda. Instead writing a square function we substituted it with a lambda expression. map() applies it to all elements in the list and returns a new list with each element square of original element.

Reduce: reduce() continuously applies a function to a sequence and returns one value. In the following example we sum all elements in the original list. Syntax: reduce (func, sequence)

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#output: 6

Filter: It filters all values in a sequence for which given function returns True. Syntax: filter (booleanFunc, sequence)

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filter (lambda x : x%2, list)
#output: [1, 3]

Above example returns all odd integers in the list. Remember 2%2=0 is treated as boolean value False.

Writing Hello World is a custom I dare not to break as I start off with this brand new blog. Here are Hello World programs in ten different programming languages.

1. The C Not only C can be termed as mother of most high level languages but it remains relevant till date. It is undoubtedly the most popular language of all times.

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#include void main() {
    printf("Hello World!");
} 

2. C ++ Bjarne Stroustrup’s language gave programmers a new world view with Object Oriented Programming.

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#include void main() {
   cout << "Hello World!";
} 

3. UNIX Shell Shell is like a Ninja’s sword! You need to see this.

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#!/bin/sh
echo "Hello World!"

4. Java Java is perhaps the only ubiquitous multi platform language we have seen.

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public class HelloWorld {
    public static void main(String args \[\]) {
       System.out.print("Hello World!");
    }
}

5. Hello World in C# C# is a great programming language based on C from Microsoft.

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public class HelloWorld {
    static void Main() {
       System.Console.Write("Hello World!");
    }
}

6. JavaScript JS shaped platforms which employ half of the Indian programmers.

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alert ("Hello World");

7. PHP PHP makes great front-ends for web applications.

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echo "Hello World!";

8. Python My favourite! Python is simple, readable and powerful.

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print ('Hello World!')

9. PL/SQL When you cannot think in SQL, you use PL/SQL!

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begin
    dbms\_output.put\_line ('Hello World!');
end;

10. Arduino C Arduino propels IoT development with affordable open source prototyping boards for everyone. Arduino-C is indeed C!

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// setup () function runs only once
void setup() {
  // Use on-board LED as output
  pinMode(LED\_BUILTIN, OUTPUT);
}

// loop function runs forever
void loop() {
  digitalWrite(LED\_BUILTIN, HIGH);   // turn the LED on
      delay(1000);                       // wait a sec (or 1000 ms)
  digitalWrite(LED\_BUILTIN, LOW);    // turn the LED off
      delay(1000);                       // wait a sec (or 1000 ms)
}

So this is how journey at iDevji starts, I hope it will create value, may be little, for everyone specially my students!