# Python Tutorial

Python is a very simple style syntax language. It uses a new line for a new statement. A line space for the scope of the functions and loops.

## Why Should You Learn?

• Python is very popular among data science and machine learning developers.
• Google, DropBox, Facebook, and Amazan companies are using Python as a major language for software development.
• It is used for numerical and mathematical computing.
• It is functional, procedural, object-oriented and also works as the scripting language.

## Python Tutorial

In this tutorial, I will  write  some programs  to illustrate the concept

• ## Sum of Two Numbers

sum=0                  #sum variable initialized to 0

x=3                    #x variable initialized to 3

y=5                    #y variable initialized to 5

sum = x + y           # Add x and y and assigns to sum

print ( sum)          # Prints sum of x and y



The Output of the program would be 8

• ## Sum of Natural Numbers

sum=0                                  #Initialize variable sum equal to zero
i=0                                          #Initialize variable i equal to zero
while i <= 10:                     # Check the condition
sum += i                              # Sum of natural numbers
i += 1                                     # Increment the variable i

print(sum)                         # Print sum of the natural numbers



The output of the program would be    55

• ## Factorial of Natural Numbers

fact=1                #Initialize variable fact equal to 1
i=1                      # Initialize variable i equal to 1
while i <= 5:    # Check the condition
fact *= i              # Calculate factorial
i += 1                  # Increment the variable i

print(fact)        # Print Factorial



The output of the program would be    120

• ## “import” statement in Python

To use modules library, Python uses import command.

For instance, if you want to use a random number generator.

You will write as

import math

and you will be able to use the function fmod (x,y).

See the program

import math

print(math.fmod(35,4))



The output of the program fmod(x, y)  function is defined in math.py library.

“as” statement with import

“as”statement is used to create an alias of library name.

The same program you can write as

 import math as m
print(m.fmod(35,4))


## Function-

A function is a block of statements that performs a specific task.

Python uses def keyword to define a function.

def add(x,y):
return x+y



Calculating factorial of a natural number

def factorial( n):
fact=1
i = 1
while i < n:
i+= 1
fact = fact * i
return fact

print(factorial(5))