# For loop

#### For loop

for loop is the most comfortable loop. It is also an entry check loop. The condition is checked in the beginning and the body of the loop(statements-block 1) is executed if it is only True otherwise the loop is not executed.

**Syntax:**

**for counter_variable in sequence:**

**statements-block 1**

**[else: # optional block**

**statements-block 2]**

The ** counter_variable** mentioned in the syntax is similar to the control variable that we used in the for loop of C++ and the sequence refers to the initial, final and increment value. Usually in Python, for loop uses the

*range()*function in the sequence to specify the initial, final and increment values.

*range()*generates a list of values starting from

**till**

*start***.**

*stop-1***Example : #program to illustrate the use of for loop - to print single digit even number**

for i in range (2,10,2):

print (i, end=' ')

**Output:**

2 4 6 8

**Example : #program to illustrate the use of for loop - to print single digit even number with else part**

for i in range(2,10,2):

print (i,end=' ')

else:

print ("\nEnd of the loop")

**Output:**

2 4 6 8

End of the loop

**Example : # program to calculate the sum of numbers 1 to 100**

n = 100

sum = 0

for counter in range(1,n+1):

sum = sum + counter

print("Sum of 1 until %d: %d" % (n,sum))

**Output:**

Sum of 1 until 100: 5050

**Example : program to illustrate the use of string in range() of for loop**

for word in 'Computer':

print (word,end=' ')

else:

print ("\nEnd of the loop")

**Output**

C o m p u t e r

End of the loop

#### Python : **For loop** Program List

**Program [1]**

WAP to calculate compound simple interest after taking the principle, rate and time.

**Program [2]**

WAP that searches for prime numbers from 15 through 25.

**Program [3]**

WAP to test if given number is prime or not.

**Program [4]**

WAP to check whether square root of a given number is prime or not.

**Program [5]**

WAP to print first n odd numbers in descending order.

**Program [6]**

WAP to find the average of the list of the numbers entered through keyboard.

**Program [7]**

WAP to find the largest number from the list of the numbers entered through keyboard.

**Program [8]**

WAP to find the sum of n natural numbers.

**Program [9]**

WAP to find the sum of first n even numbers.

**Program [10]**

WAP to find the sum of first n odd numbers.

**Program [11]**

WAP a program to generate a list of elements of Fibonacci Series.

**Program [12]**

Write a program to input any number and to print all natural numbers up to given number.

**Program [13]**

Write a program to input any number and to find sum of all natural numbers up to given number.

**Program [14]**

Write a Python program to accept a integer number form user and find the factorial value of input number.

The factorial of a number is the product of all the integers from 1 to that number. For example, the factorial of 6 is 1*2*3*4*5*6 = 720 . Factorial is not defined for negative numbers, and the factorial of zero is one, 0! = 1 .

Sample:

Input : 5

Output : 120

**Program [15]**

Write a Python program to input any number and print all factors of input number.

A factor is a number that divides into another number exactly and without leaving a remainder.

Sample:

Input : 12

Output : Factor of 12 are : 1,2,3,4,6 ,12

**Program [16]**

Write a Python program to accept a integer number from user and check number is composite Number or not.

Composite number is a whole numbers that have on 1 or more than 1 factors excluding 1 and itself.

**Program [17]**

write a program to print the table of a given number. The number has to be entered by the user.

**Program [18]**

write a program to calculate the sum of odd numbers divisible by 5 from the range 1..100

**Program [19]**

Write a program to print Floyd's triangle as shown below:

1

2 3

4 5 6

7 8 9 10

11 12 13 14 15