What is The Difference Between For and While Loop in Python?

If you are an engineering student or a practicing engineer, understanding the fundamentals of the programming language or any other tools you use to develop your project is a must. Just like the loops. Without Loops, any programming language would have long and complex codes. Loops are a fundamental component of all programming languages that makes code short and more understandable. 

In this blog, we will discuss the notion of loops as well as the basic differences between Python’s two most used loops, for and while, and what these loops are primarily used for. 

What are Loops and why Loops are Used?

Let’s say you want to run a piece of code multiple times. Instead of writing it several times for each execution, you could place it inside a loop. And under certain circumstances or conditions, that loop will run and its code will be carried out.

In technical words – A loop can be defined as a programming structure used in computer science that repeatedly executes a set of instructions up until a certain condition is satisfied. Loops are a common tool used by programmers to repeat functions, cycle through values, and perform a variety of other tasks. All contemporary programming languages, albeit they may have different implementations and syntax, support loops. The while loop and the for loop are two of the most used loop types.

Loops in Python

Python offers three options for running the loops. The core functionality of all the methods is the same, although their syntax and the amount of time required for condition checking vary.

  1. For Loop: Python’s for loop is used to repeatedly iterate over a sequence (list, tuple, set, dictionary, and string). 
  2. While Loop: While a condition is true, a set of statements are carried out in a while loop. 
  3. Nested Loop: A loop is referred to as being nested if it is included within the body of another loop

Difference between For and While Loop in Python

1. For Loop

Python’s for loop is used to repeatedly loop through a list, tuple, string, or another iterable object. This functions more like an iterator method than the for keyword seen in other programming languages.

The value of each item in the sequence that exists before the iteration starts is kept in this case by the variable value until the iteration is finished. The loop keeps going until it reaches the last item on the list.



Break Statement

The loop that contains the break statement is ended as soon as the break statement is executed. Following the body of the loop, the statement receives control of the program. 



Continue Statement

The break statement forces us to break from the loop and continue the next peace of code in the sequence whereas the Continue statement just skips from the loop for the condition given in the continue statement and the loop continues for all the other values. In short – The continue statement does not end the loop; rather, it continues with the following iteration.



Else in For Loop

The else block is an optional addition to a for loop. If the elements in the sequence are utilized in the for loop exhaust, the else portion is executed. 



Nested For Loop

An interlocking loop is referred to as nested. Every time the “outer loop” iterates, the “inner loop” will be run once:



2. While Loop

As long as the supplied condition, i.e., conditional expression, is true, the Python while loop iteration of a code block is run. An indefinite loop can be created if we don’t know in advance how many times we’ll perform the iteration. 

In the Python programming language, a while loop has the following syntax:

A statement or combination of statements in this case might be singular or collective. Any expression that fulfills the requirement and does not equal zero is true for the condition. While the condition stays true, the loop keeps iterating. The line immediately after the loop receives program control when the condition is false. 

Python takes advantage of indentations in the code to show where the body of the while loop is. The first line without an indent signals the end of the body, which is initially indented.



The while loop’s important feature in this situation is that it might never run. The body of the while loop is skipped and the first statement following it is performed when the condition is tested and the result is false.

While Loop with Else

While loops can optionally have an optional else block, just like for loops. If the condition in the while loop evaluates to False, the otherwise portion is run. A while loop can be terminated using a break statement. The else part is ignored in this situation. Therefore, if there is no break and the condition is false, the else portion of a while loop executes.



When to use For & While Loop?

While both the 

r loop and the while loop are iteration statements, each has a unique property. The initialization, condition, and iteration of the for loop are all declared at the beginning of the loop’s body. On the other hand, in a while loop, only the initialization and condition are at the top of the body of the loop, and iteration can be added anywhere else.

When we already know the number of iterations, or how many times a sentence must be processed, the for loop is employed. Because of this, the ending point must be specified when the for loop is initialized. 

We use a while loop when we need to end the loop based on something other than the number of repetitions. It is not necessary to know the condition ahead in this situation. Because of this, when initializing the loop, we can provide a boolean expression.


The Python programming language For and While loops were thoroughly discussed in this blog. How we properly handled the topic and strengthened your comprehension of it. If you want to learn more about python and cover all the basic aspects of it as well, please feel free to enroll in Board Infinity’s Python Programming Certification Course and learn from the best in the industry.

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