Hello in this tutorial, we will see how to use to while loop in python programming.
1. Introduction
The while loop allows the code to be executed until the given condition returns false. The while loop is also known as the pre-tested loop. It is represented by the syntax as:
Syntax
while EXPRESSION: STATEMENT(S)
Here the STATEMENT(S) can be a single statement or a group of statements. The while loop consists of some loop control statements such as:
continue: It transfers the control to the beginning of the loop for the next iteration and exits the current iteration of the loopbreak: It brings the control out of the current loop. It is commonly used to terminate the loop when a certain condition is metelse: It is an optional clause and executed only when the expression evaluates tofalse. Make note that if an exception is thrown or the loop is terminated with thebreakstatement theelseblock won’t be executed
1.1 Single statement suites
If a while loop consists of a single statement it is known as the single statement suites. We will understand with a practical example.
1.2 Setting up Python
If someone needs to go through the Python installation on Windows, please watch this link. You can download the Python from this link.
2. While Loop in Python
Let us dive in with the programming stuff now. I am using JetBrains PyCharm as my preferred IDE. You’re free to choose the IDE of your choice.
2.1 Creating an implementation file
Let us understand the implementation with the help of a python script.
Implementation file
# python while loop example
# while loop
def while_loop():
i = 1
while i < 11:
print('counter = {}'.format(i))
i += 1
# while loop with else
def while_else():
i = 1
while i < 6:
print('counter = {}'.format(i))
i += 1
else:
print('loop completed')
# while loop and break statement
def while_break():
i = 1
while i < 11:
if i == 5:
print('counter reached threshold. breaking loop')
break
else:
print('counter = {}'.format(i))
i += 1
# while loop and continue statement
def while_continue(brand):
i = 0
while i < len(brand):
if brand[i] == 'a' or brand[i] == 'd':
i += 1
# skipping alphabets - 'a' and 'd'
continue
print('current alphabet = {}'.format(brand[i]))
i += 1
# single statement suites
def single_statement_suites():
flag = 1
while flag: print('printing single statement suites'); flag -= 1
print('done')
if __name__ == '__main__':
# while_loop()
# while_else()
# while_break()
# while_continue('android')
# single_statement_suites()
You can uncomment the method of your choice and run this python script. If everything goes well the output will be shown in the IDE console.
Console output
==== while loop ==== counter = 1 counter = 2 counter = 3 counter = 4 counter = 5 counter = 6 counter = 7 counter = 8 counter = 9 counter = 10 ==== while loop with else ==== counter = 1 counter = 2 counter = 3 counter = 4 counter = 5 loop completed ==== while loop and break statement ==== counter = 1 counter = 2 counter = 3 counter = 4 counter reached threshold. breaking loop ==== while loop and continue statement ==== current alphabet = n current alphabet = r current alphabet = o current alphabet = i ==== single statement suites ==== printing single statement suites done
That is all for this tutorial and I hope the article served you with whatever you were looking for. Happy Learning and do not forget to share!
3. Summary
In this tutorial, we learned:
whileloop in the python programming- Sample programming stuff
You can download the source code of this tutorial from the Downloads section.
4. More articles
5. Download the Project
This was a tutorial to understand the while loop in python programming.
You can download the full source code of this example here: While Loop in Python
Last updated on Feb. 24th, 2022
