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