Welcome to Python functions! A function is a reusable block of code that performs a specific task. Functions help us organize our code better, avoid repetition, and make our programs more modular. Here's a simple example of a function that greets a person by name.
Let's explore the syntax and structure of Python functions. Every function starts with the def keyword, followed by the function name and parentheses. Parameters go inside the parentheses, and a colon ends the definition line. The function body must be indented. You can have functions with no parameters, with multiple parameters, or with default parameter values.
Now let's understand parameters and arguments. Parameters are the variables defined in the function, while arguments are the actual values you pass when calling the function. Python supports positional parameters where order matters, keyword arguments where you specify the parameter name, and default parameters that have preset values. You can mix these different types when calling functions.
Let's explore return values and variable scope. Functions can return values using the return statement. If no return is specified, the function returns None by default. You can also return multiple values as a tuple. Variable scope determines where variables can be accessed. Local variables exist only inside the function, while global variables can be accessed from anywhere in the program.
To summarize what we've learned about Python functions: Functions are reusable blocks of code that help organize your programs. They use the def keyword and support various parameter types. Functions can return values and follow scope rules for variable access. Mastering functions is essential for writing clean, efficient Python code.