Python Decision Making

Decision-making is the way where a program shift execution from one side to another based on a condition if the condition evaluates to True then the next statement(s) will be executed other wise if there is any else statement its block(or body) will be executed instead.

True vs False vs not

True

All non 'None' values, not empty string, non-zero numbers, whitspace-only strings, and not False values are True

False

All None, empty string, False values are considered False

not

not keyword is used to counter the condition value:

#!/usr/bin/env python


if not True == False:
   print("not True equals False")
   
   
if not False == True:
   print("not False equals True")
   

Output

not True equals False
not False equals True

.

• if statements

  An if statement consists of a boolean expression followed by one or more statements.

• if...else statements

  An if statement can be followed by an optional else statement, which executes when the boolean expression is False.

• Nested if statements

  You may use one if or else if statement inside another if or else if statement(s). however keeping decision flow flat and simple is encouraged

#!/usr/bin/env python

home = 'coderme.com'

if 'coderme' in home:
   print("Home contains 'coderme'")

Output

Home contains 'coderme'