Python While Loops

Python While Loop is used to execute a block of statements repeatedly until a given condition is satisfied. When the condition becomes false, the line immediately after the loop in the program is executed.

while expression:
statement(s)               
              

i = 1
while i < 5:
  print(i)
  i += 1              
              

Flowchart of While Loop

While loop falls under the category of indefinite iteration. Indefinite iteration means that the number of times the loop is executed isn’t specified explicitly in advance.

The break Statement

With the break statement we can stop the loop even if the while condition is true:

while i< 5:
 print(i)
 if i  == 4:
  break              
   i += 1          
 
  Output
  1
  2
  3
  4
  
              

The continue Statement

With the continue statement we can stop the current iteration, and continue with the next:

i= 0
 while i < 6:
i+= 1
 if i  == 4:
    continue              
   print (i)        


  
  Output
  1
  2
  3
  4
  5
  6
  
              

The else Statement

With the else statement we can run a block of code once when the condition no longer is true:

 i= 1
while i < 5:
 print(i)
  i += 1            
   else:          
 print("i is no longer less than 5")
 
 
  Output
  1
  2
  3
  4
  i is no longer less than 5