Practice in interactive mode

• Run Idle on your machine
  

  python3

• Write a while loop
  

  >>> numb = 0
  >>> while numb < 10:
  ...     numb = numb + 1
  ...
  >>> numb

• Write a while loop to add the numbers from 1 to 100
  

  >>> num = 0
  >>> total = 0
  >>> while num <= 100:
  ...     num = num + 1
  ...     total = total + num
  ...
  >>> total
  5151

• Write a data validation loop
  

  >>> done = False
  >>> while not done:
  ...     num = int(input('Please enter a number greater than 0: '))
  ...     if num > 0:
  ...             done = True
  ...     else:
  ...             print(num, 'is not greater than 0')
  ... 

• Write an infinite loop
  

  >>> while True:
  ...    print("Are we there yet?")

  You many have to hit Control C many times to stop this loop.

Code for this Exercise

• Open a text editor
  A program like Sublime.
  Do not use Word or Notepad.
• Copy the text below into the file

• Save the file as ex9.py
  
• Run this script in IDLE
  Open the script file in IDLE. Under the Run menu, select Run Module.
• You should see something like this
  

  Entering while loop
  number: 0
  number: 1
  number: 2
  number: 3
  Left while loop
  number: 4
  
  The sum of all the numbers from 1 to 100 is 5050
  
  Are we there yet? no
  Are we there yet? no
  Are we there yet? no
  Are we there yet? yes
  Yeah!
  
  Please enter an integer greater than 0: -1
  -1 is not greater than 0
  Please enter an integer greater than 0: 0
  0 is not greater than 0
  Please enter an integer greater than 0: 5
  5