Branching statements in Python

View more categories:

1- Comparison operators

The common comparison operators:
Operator Meaning Example
> greater than 5 > 4 is true
< less than   4 < 5 is true
>= greater than or equal 4 >= 4 is true
<= less than or equal  3 <= 4 is true
== equal to 1 == 1 is true
!= not equal to  1 != 2 is true
and and a > 4 and a < 10
or or a == 1 or a == 4

2- if-else statement

if is a statement which checks  a certain condition in Python. For example: If a> b, then do something ....
 
Syntax:
if condition_1 :
    # Do something

elif condition_2 :
    # Do something

elif condition_N:
    # Do something

else :
    # Do something
 
The program checks the condition from top to bottom until it encounters a condition that is true, and run this block and the program does not check the remaining conditions in the branching structure.
Example (if - else):
ifElseExample.py
option = 5


if option == 1:
   
    print("Hello")
   
else :
   
    print("Bye!")   
Example (if - elif - else):
ifElseExample2.py
print("Please enter your age: \n")

# Declare a variable to store the user input from the keyboard.
inputStr =  input()

# int(..) function convert string to integer
age = int(inputStr)

# Print out your age
print("Your age: ", age)

# If age < 80 then ..
if (age < 80) :

    print("You are pretty young")

# Else if age between 80, 100 then
elif (age >= 80 and age <= 100) :

    print("You are old")

# Else (Other case)
else :

    print("You are verry old")
Running the example:

View more categories: