### Repetitive Statements

- When we are assigned home work from our teacher will she say something like write number from 1 to 100 or will she write all the numbers
- Lets look at our code

```
print(1)
print(2)
print(3)
print(4)
print(5)
print(6)
print(7)
print(8)
print(9)
print(10)
```

- Now if we want to get the same thing done from our python3, we need to understand looping structures. Lets look at
**while** - in the above code only number is changing, so if we make number dynamic rather than static will it help?

```
while <condition>:
<block>
```

- Lets adopt this to our above program

```
index = 1
while index <= 10:
print(index)
index = index + 1
```

#### Write a program to print all the even numbers from 1 to 100

- Lets speak with Jarvis

```
Hi jarvis
start from 1 till 100 and remember this as index
check if index%2 == 0 and if it is yes print index
```

- Now our python program will be something like

```
index = int(input("Enter the starting number :"))
end = int(input("Enter the ending number :"))
while index <= end:
if index%2 == 0:
print(index)
index = index + 1
```

#### Write a program to calculate factors of a number given by user

- Lets speak with Jarvis

```
Hi Jarvis,
Accept input from user and remember as number
start from 2 till number-1 and remember as index
check if number is divisible by index , if yes print index
```

#### Exercise: Write a python programs

- Write a program to find if the input is prime or not?
- Project Euler Problem 1
- Project Euler Problem 2
- Project Euler Problem 3