Use of continue in python

Question

hey, I am confused with continue and break statement. Can anyone please tell me what is the practical use of "continue" statement in python?

Answer 1

The break statement is used to "break" the loop. It means that when a break statement is executed, it skips the execution below it in the loop and exits the loop. 

Ex: 

for letter in 'HelloWorld':    
    if letter == 'W':
        break
    print 'Character is:', letter

Output for this code will be:

Character is: H

Character is: e

Character is: l

Character is: l

Character is: o

The continue statement is used to continue the loop by skipping the execution of code below it i.e., when a continue statement is executed, it skips executing the code below it but goes back to the loop and continues with the next cycle.

Ex:

for letter in 'Hello':    
    if letter == 'H':
        continue
    print 'Character is: ', letter

Output for this code will be:

Character is: e

Character is: l

Character is: l

Character is: o

Answer 2

Here's an simple example :

for letter in 'Django':    
    if letter == 'D':
        continue
    print 'Current Letter:', letter

Output will be :

Current Letter: j
Current Letter: a
Current Letter: n
Current Letter: g
Current Letter: o

Answer 3

Usually the situation where continue is necessary/useful, is when you want to skip the remaining code in the loop and continue iteration.

I don't really believe it's necessary, since you can always use if statements to provide the same logic, but it might be useful to increase readability of code.

Answer 4

import random  

for i in range(20):  
    x = random.randint(-5,5)  
    if x == 0: continue  
    print 1/x  

continue is an extremely important control statement. The above code indicates a typical application, where the result of a division by zero can be avoided. I use it often when I need to store the output from programs, but dont want to store the output if the program has crashed. Note, to test the above example, replace the last statement with print 1/float(x), or you'll get zeros whenever there's a fraction, since randint returns an integer. I omitted it for clarity.

Answer 5

Suppose you need a check before the main code:

if precondition_fails(message): continue

''' main code here '''

Note you can do this after the main code was written without changing that code in anyway. If you diff the code, only the added line with "continue" will be highlighted since there are no spacing changes to the main code.

Answer 6

def filter_out_colors(elements):
  colors = ['red', 'green']
  result = []
  for element in elements:
    if element in colors:
       continue # skip the element
    # You can do whatever here
    result.append(element)
  return result

  >>> filter_out_colors(['lemon', 'orange', 'red', 'pear'])
  ['lemon', 'orange', 'pear']