Defining and Calling Functions

To define a function in Python, you can use the “def” keyword followed by the name of the function and a set of parentheses that may include parameters. The code inside the function is indented, and you can use the “return” keyword to specify a value to be returned when the function is called. The syntax for defining a function in Python is as follows:

def function_name(parameters):
    # code to be executed
    return value

For example, consider the following code:

def greet(name):
    message = "Hello, " + name
    return message

In the above example, we defined a function called “greet” that takes a parameter called “name” and returns a greeting message with the name included.

To call a function in Python, you can use the name of the function followed by a set of parentheses that may include arguments. The syntax for calling a function in Python is as follows:

function_name(arguments)

For example, consider the following code:

greeting = greet("John") 
print(greeting)

The output of this code will be “Hello, John”.

In the above example, we called the “greet” function with the argument “John” and assigned the returned value to a variable called “greeting”. We then printed the value of “greeting” to the screen.

When defining a function in Python, you can specify one or more parameters in the parentheses. These parameters are placeholders for the values that will be passed to the function when it is called.

When calling a function, you can pass one or more arguments in the parentheses. These arguments are the actual values that will be used in the function.

For example, consider the following code:

def add(x, y):
    result = x + y
    return result

sum = add(3, 4)
print(sum)

The output of this code will be “7”.

In the above example, we defined a function called “add” that takes two parameters, “x” and “y”.

To use the “return” keyword in a function in Python, you can specify the “return” keyword followed by a value or expression to be returned when the function is called. The syntax for using the “return” keyword in a function is as follows:

def function_name(parameters):
    # code to be executed
    return value

For example, consider the following code:

def add(x, y):
    result = x + y
    return result

sum = add(3, 4)
print(sum)

The output of this code will be “7”.

In the above example, we defined a function called “add” that takes two parameters, “x” and “y”, and returns the sum of these values using the “return” keyword. When we called the function with the arguments “3” and “4”, the values of “x” and “y” were set to “3” and “4” respectively, and the function returned the sum “7”.

To specify default values for function parameters in Python, you can assign a value to the parameter when defining the function. If the function is called without an argument for that parameter, the default value will be used. The syntax for specifying default values for function parameters is as follows:

def function_name(parameter=default_value):
    # code to be executed

For example, consider the following code:

def greet(name="John"):
    message = "Hello, " + name
    return message

greeting = greet()
print(greeting)

The output of this code will be “Hello, John”.

In the above example, we defined a function called “greet” that takes a parameter called “name” with a default value of “John”. When we called the function without an argument, the default value was used, and the function returned the greeting message “Hello, John”.