Function Calling

In Python, after defining a function, it needs to be called to execute the statements it contains. This concept is referred to as ‘function calling’.

Basic Function Calling#

A function is called by using its name followed by parentheses (), sometimes enclosing arguments, if the function requires them.

Consider the following function that prints a greeting message:

1def print_greeting():
2    print("Hello, Codebay readers!")

You can call this function like so:

1print_greeting()  

Running the above code will output: Hello, Codebay readers!

Function Calling with Arguments#

When a function is designed to take arguments, values must be passed into the function during the call. These input values are referred to as arguments.

For instance, consider a function that adds two numbers:

1def add_numbers(a, b):
2    print(a + b)

We can call this function by providing two arguments:

1add_numbers(5, 3)  

This will output 8.

Calling a Function from another Function#

In Python, a function can be called from another function. This is useful for breaking down complex tasks into smaller, more manageable functions.

Consider a situation where we want to greet a user and then ask them a question:

 1def greet():
 2    print("Hello!")
 3  
 4def ask_question():
 5    print("How are you today?")
 6  
 7def converse():
 8    greet()
 9    ask_question()
10  
11converse()

In the above code, calling the converse() function will first execute the greet() function, printing out “Hello!” and then execute the ask_question() function, printing out “How are you today?”.

Function calling is a fundamental concept in Python, and it enhances code reusability and clarity. It’s a good practice to encapsulate repetitive or related tasks within a function and then call them as needed.