Python else Keyword



In Python, the else keyword is used in conditional statements. The else block will be executed only when the if condition is False. This keyword is syntactically dependent on the if keyword. When we use use else keyword without an if statement we will get an SyntaxError.

Syntax

Following is the syntax of Python else keyword −

if condition:
       statement1
	   statement2
else:
    statement3
	statement4

Example

Following is a basic example of Python else keyword −

if False:
    print("Hello")
else:
    print("Hello world")

Output

Following is the output of the above code −

Hello world

Using else Keyword In Functions

The else keyword can also be used in the functions to check conditional statements.

Example

Here, we have defined a function named fun1 to check whether the number is positive or not −

def fun1(num):
    if num<0:
        return False
    else:
        return True
x=9
print(x,"is a positive number :",fun1(x))
y=-4
print(y,"is a positive number :",fun1(y))

Output

Following is the output of the above code −

9 is a positive number : True
-4 is a positive number : False

Using else Keyword in Loops

The else keyword is used in loops based on the conditional statements.

Example

Lets try to understand else keyword in loops −

x=[1,2,3,4]
for i in x:
    if i%2==0:
        print(i,"is a even number in the list")
    else:
        print(i,"is not a even number in the list")

Output

Following is the output of the above code −

1 is not a even number in the list
2 is a even number in the list
3 is not a even number in the list
4 is a even number in the list

Using else keyword without if statement

The else keyword depends on if condition. If we will use else block without if condition we will get an SyntaxError.

Example

else: 
    print("Hello")

Output

Following is the output of the above code −

 File "E:\pgms\Keywords\else.py", line 28
    else:
    ^^^^
SyntaxError: invalid syntax

Using else keyword with elif

When there are more than one conditional statement to check we can use elif. If all the given conditions are False than else block will be executed.

Example

Here, is an example for usage of else along with elif keyword −

if False:
    print("Welcome")
elif False:
    print("To")
elif False:
    print("the")
else:
    print("Welcome to Tutorials Point")

Output

Following is the output of the above code −

Welcome to Tutorials Point

Using else with try & except block

We can also use else keyword with try and except block. In this the else block is executed only if try block will not raise any error.

Example

Lets try to execute else along with try and except block −

x = 5
try:
    x < 10
    print("This statement is executed")
except:
  print("Something went wrong")
else:
  print("This statement is executed only if try block is executed without raising any errors")

Output

Following is the output of the above code −

This statement is executed
This statement is executed only if try block is executed without raising any errors

Nested else

When there are multiple else within a single else block is known as nested else.

Example

Here, is an example for nested else −

if False:
    print("This is not executed")
else:
    if False:
        print("Hello World")
    else:
        print("This statement is executed")

Output

Following is the output of the above code −

This statement is executed
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