How to Use the Break Statement in Python

Control flow is a fundamental concept in programming. Programmers often create loops and test conditions which need to be escaped from early. Using Python's break statement, you can implement a way to terminate out of for and while loops.

Difficulty: Easy

Instructions

Use the Break in a For loop

1. Create a for loop which you may wish to break out of early:for k in range(5,10):

2. Determine the conditions that need to be met to leave the loop early.

3. Use an if/else statement inside the for loop to leave the loop early. You may use the break statement inside the nested if/else statement: for k in range(5,10):
     if k == 7:
    print 'breaking out of the loop!'
    break
  else:
    print kThis sample loop logic will print:  5
  6
  breaking out of loopAnd then terminate.

4. Understand that the control variable in for loops retain its value after the break. In the above example, the value of k will be 7.

Use the Break in a While Loop

5. Create a while loop that you may wish to break out of early: while i < 15:

6. Determine the conditions that need to be met to leave the loop early.

7. Use an if/else statement inside the for loop to leave the loop early. You may use the break statement inside the nested if/else statement:
   i=0
while i < 15:
  i = i+1
  print i
  if i == 4:
    print 'breaking out of loop'
    break
  else:
    print i
This will print:
1
2
3
breaking out of loop

Tips & Warnings

• If you are using a break statement within a try / except / finally statement inside a loop, the finally clause will be evaluated if the break is caught.
• Guido Van Rossum's Python tutorial is a great place to start learning the basics of Python, as well as generally learning how to program (see Resources below).
• You may only use the break statement in Python inside a while or for loop.

Resources

• Guido Van Rossum's Python tutorial