Required arguments in Python

Required arguments are the arguments passed to a function in correct positional order. Here, the number of arguments in the function call should match exactly with the function definition.

To call the function printme(), you definitely need to pass one argument, otherwise it gives a syntax error as follows ?

Example with Missing Required Argument

# Function definition is here
def printme(str):
    "This prints a passed string into this function"
    print(str)
    return

# Now you can call printme function
printme()

When the above code is executed, it produces the following result ?

Traceback (most recent call last):
  File "<string>", line 7, in <module>
TypeError: printme() missing 1 required positional argument: 'str'

Correct Function Call with Required Argument

To fix this error, we must pass the required argument when calling the function ?

# Function definition is here
def printme(str):
    "This prints a passed string into this function"
    print(str)
    return

# Correct function call with required argument
printme("Hello Python!")
printme("This is a required argument example")

Hello Python!
This is a required argument example

Multiple Required Arguments

Functions can have multiple required arguments that must be passed in the correct order ?

def calculate_area(length, width):
    "Calculate area of a rectangle"
    area = length * width
    print(f"Area of rectangle: {area}")
    return area

# All required arguments must be provided
calculate_area(5, 3)
calculate_area(10, 7)

Area of rectangle: 15
Area of rectangle: 70

Key Points

• Required arguments must be passed in the exact order defined in the function
• The number of arguments in the function call must match the function definition
• Missing any required argument results in a TypeError
• Required arguments are also known as positional arguments

Conclusion

Required arguments are essential parameters that must be provided when calling a function. They ensure functions receive all necessary data to execute properly and maintain code reliability.