Assign Function to a Variable in Python

Functions are first-class objects, which means they can be assigned to variables just like any other value. Once a function is assigned to a variable, the function can be called using either the original function name or the variable.

GFG

Explanation:

• show is a function that prints "GFG".
• func = show assigns the function reference to the variable func.
• Calling func() executes the show() function

Note: When assigning a function to a variable, use the function name without parentheses. Writing func = show assigns the function itself, while func = show() executes the function and assigns its return value.

Syntax

def function_name(parameters):
# function body
pass

variable_name = function_name
variable_name(arguments)

Where:

• function_name is the name of the function.
• variable_name stores the reference to the function.
• variable_name(arguments) calls the function through the variable.

Examples

Example 1: The following example demonstrates assigning a function to a variable and calling it using that variable. It also shows the difference between local and global variables.

123
98
123
98
123

Explanation:

• global variable x has the value 123. Inside display(), a local variable x with value 98 is created.
• globals()['x'] accesses the global variable x, a = display assigns the function to the variable a and calling a() executes the display() function.

Example 2: The following example assigns a function that accepts a parameter to a variable and calls it using that variable.

Odd number
Even number
Odd number

Explanation:

• check(num) determines whether a number is even or odd.
• a = check assigns the function to the variable a.
• Calling a(num) executes the check() function with the given argument.

Example 3: The following example assigns a function that returns a value to a variable and calls it using that variable.

240
400
4000

Explanation:

• multiply(num) returns num * 40 and a = multiply stores a reference to the function in a.
• Calling a(num) executes the function and returns the calculated value.