## Looping constructs in Python while and for

• Repeat with While:
• This is simplest mechanism for looping
• The syntax is
``````while <conditional expression>:
# code block
``````
• Examples
• Lets try to write a program which prints all the even numbers between 10 and 50
• Lets write a program to find the factors of a given number
``````  number = int(input('Enter the number: '))
index = 2
while index < number:
if number%index == 0:
print(index)
index += 1

``````
• Lets modify the above program to print only last 5 factors
``````  number = int(input('Enter the number: '))
index = number -1
factors_found = 0
while index >= 2:
if number%index == 0:
if factors_found < 5:
print(index)
factors_found += 1
if factors_found == 5:
break

index -= 1

``````
• Exercise: Write a python program to find out if the number given is prime or not
``````  number = int(input('Enter the number: '))
index = 2
is_prime = True
while index < number:
if number%index == 0:
is_prime = False
break
index += 1

if is_prime:
print(f"{number} is prime")
else:
print(f"{number} is not prime")
``````
• Exercise: Extend the program to print all the prime numbers between 10 and 100

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