Mastering Function Calls: Python's Keyword Arguments

Till now, you have learned about Python functions and the scope of variables in Python but that topic is hard to grasp at first because it is vague.

Python came up with a solution to resolve this issue. It is simple to name the arguments whenever you call a function. This technique is simple but at the same time very effective in understanding the Python functions. In this article, you will be learning in-depth about Keyword Arguments and how it is used for naming arguments whenever a function is called.

In Python, Keyword Arguments is a special method that allows you to specify the name of the argument when you call a function, along with its value. This makes it easier to understand what each value represents, regardless of their order.

Whenever you define a function, you can give some default parameters as its default values. These values are used if you don't provide any values when you call the function. Now, when you call the function, instead of just passing values in the same order as the parameters, you can use the names of the parameters and their corresponding values. This way, you can be more explicit about which value is meant for which parameter, even if they're not in the same order as the function's definition.

Using keyword arguments yields you many benefits and makes you stand out as a Python programmer. Let us see the benefits of keyword arguments:

• Explicitness: Keyword arguments make the function call more explicit, as you can clearly see which value is assigned to which parameter, regardless of their order.
• Readability: Keyword arguments enhance the readability of code, as they make the function call self-explanatory.
• Default values: Keyword arguments are especially useful when a function has parameters with default values. By using keyword arguments, you can selectively override only the desired default values without providing values for all the parameters.

To understand the concept and the working procedure, let's use the example of a function called 'greet()' that greets a person with a custom message.

Here's a step-by-step breakdown of the example using keyword arguments:

1. Function definition:

 >>> def greet(name, message="Hello"):
 >>> print(message + ", " + name + "!")

In this function, we define two parameters: 'name' and 'message'. The 'name' parameter is a required parameter, while the 'message' parameter has a default value of "Hello" assigned to it. If no value is provided for 'message' when the function is called, it will default to "Hello". Inside the function, we print the greeting message by concatenating the 'message', ", ", and 'name' using the + operator.

2. Function call with keyword arguments:

 >>> greet( **name** ="Alice")

Here, we call the 'greet()' function and provide a keyword argument 'name' with the value "Alice". Since we didn't specify a value for the 'message' parameter, it will use the default value of "Hello". The function then prints the greeting message.

3. Matching the arguments to parameters:

The provided keyword argument 'name="Alice"' is matched to the 'name' parameter, and the default value "Hello" is assigned to the 'message' parameter.

4. Printing the greeting:

Inside the function, the greeting message is printed: print(message + ", " + name + "!") In this case, the 'message' value is "Hello" (default value) and the 'name' value is "Alice". The function prints "Hello, Alice!".

By using keyword arguments, we explicitly specify which value is assigned to each parameter. This makes it clear that "Alice" is assigned to the 'name' parameter and that the default value of "Hello" is used for the 'message' parameter. Keyword arguments provide flexibility, and readability, and allow us to selectively override default values by providing specific values for desired parameters.

In conclusion, by using keyword arguments, we can improve code readability, make function calls self-explanatory, and selectively override default parameter values. This approach allows us to easily understand the purpose of each argument, regardless of their order and provides a convenient means to work with functions that have multiple parameters or default values.

I hope you understood this concept clearly, practice it again and again to get a grip on it, and over time, you will master this topic. If you have any questions regarding the topic, feel free to contact us.