Control Statements

Loops

In general, statements are executed sequentially − The first statement in a function is executed first, followed by the second, and so on. There may be a situation when you need to execute a block of code several number of times. A loop statement allows us to execute a statement or group of statements multiple times.

Python programming language provides the following types of loops to handle looping requirements.

• while loop
• for loop
• nested loops

Loop Control Statements

The Loop control statements change the execution from its normal sequence. When the execution leaves a scope, all automatic objects that were created in that scope are destroyed.

Python supports the following control statements.

• break: Terminates the loop statement and transfers execution to the statement immediately following the loop.
• continue: Causes the loop to skip the remainder of its body and immediately retest its condition prior to reiterating.
• pass: Used when a statement is required syntactically but you do not want any command or code to execute.

iterable

It is a sequence of values like string, list, tuple, dictionary, range()

Syntax:

for item in iterable:
    # do something on item

Syntax:

while expression:
    # iterates till the condition is true

The while Loop

Repeats a statement or group of statements while a given condition is TRUE. It tests the condition before executing the loop body.

Syntax:

while expression:
    # iterates till the condition is true

Example:

The break Statement

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

Example:

The continue Statement

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

Example: