Python Decision Making


Decision making structures require that the programmer specify one or more conditions to be evaluated or tested by the program, along with a statement or statements to be executed if the condition is determined to be true, and optionally, other statements to be executed if the condition is determined to be false.

Following is the general form of a typical decision making structure found in most of the programming languages:

Decision making statements in Python

Python programming language assumes any non-zero and non-null values as true, and if it is either zero or null, then it is assumed as false value.

Python programming language provides following types of decision making statements. Click the following links to check their detail.

if statementsAn if statement consists of a boolean expression followed by one or more statements.
if...else statementsAn if statement can be followed by an optional else statement, which executes when the boolean expression is false.
nested if statementsYou can use one if or else if statement inside another if or else if statement(s).

Single Statement Suites:

If the suite of an if clause consists only of a single line, it may go on the same line as the header statement.

Here is an example of a one-line if clause:


var = 100

if ( var  == 100 ) : print "Value of expression is 100"

print "Good bye!"

When the above code is executed, it produces the following result:

Value of expression is 100
Good bye!