Python Functions - Chapter 5

A group of statements that perform a specific task within a program. Functions are like mini-programs that can be executed to accomplish a larger program's goal.

A program where each task is handled by its own dedicated function. Functions break down a large program into smaller, manageable pieces.

Functions make code easier to read, understand, and manage. Writing once and using multiple times reduces repetition, saving time and effort.

Functions provided by default with Python, always available to use. Examples include 'print()', 'len()', 'type()', 'int()', 'str()', 'float()'.

Functions created by users to perform specific tasks. Defined using the 'def' keyword.

Small, anonymous functions defined using the 'lambda' keyword. They contain only a single expression.

Functions operating on other functions. They take functions as arguments, return a function, or both.

Variables defined inside a function. They are local to that function and are not accessible from outside.

Keyword arguments make code easier to read and allow you to define the order you want arguments to be assigned to

Arbitrary Arguments (*args) allow a function to accept a variable number of positional arguments. These arguments are collected into a tuple.

A variable that can be accessed anywhere in a program, including within functions. If a function needs to assign a value to a global variable, it must be redeclared within the function.

Global constants are global names that reference values that cannot be changed. They are often used to simulate global constants in Python.

A collection of pre-written functions included with Python, providing common programming tasks. These functions are seen as "black boxes" by programmers, meaning they are used without knowing their internal details.

Files that store functions from the standard library, helping to organize functions not built into the Python interpreter. They are copied to your computer during Python installation.

A line of code used to access functions stored in modules. It's written at the beginning of a program and has the format: import module_name.

A function used to generate random numbers, including those used in programming tasks.

A notation used to call a function from a specific module. Its format is: module_name.function_name().

The main function is the starting point of a Python program. It's called automatically when you run the script. It calls other functions as needed and defines the program's overall flow.

Indentation in Python is crucial. It's how the interpreter understands the structure of your code. Every block of code within a function or loop needs to be indented with the same number of spaces. Use either tabs or spaces for indentation, but be consistent.

A local variable is created and exists only within the function where it's defined. It can't be accessed outside of that function. Think of it as a private item belonging to a specific room in the house (function).

Scope refers to the region of your code where a variable can be accessed. For a local variable, its scope is limited to the function it's defined in. It's like a variable's own area of influence.

You can send pieces of data called arguments into a function to use within its calculations. Think of arguments as ingredients for a recipe (function). The recipe needs them to work correctly.

Positional arguments are placed in the exact order they appear in the function's definition. Think of it like a checklist of ingredients in a recipe; they must be added in the right order.

Keyword arguments are passed to a function using their names, so you can change the order. Think of ingredients with labels so you can add them in any order to the recipe.

Arguments are classified based on how they function in a program. They can be divided into positional, keyword or other types, Think of different types of ingredients for a recipe.

A module in Python's standard library that provides useful functions for mathematical calculations. It includes constants like pi and e, and functions for operations like sine, cosine, square root, and more.

The math module must be imported into your program before you can use its functions. You do this by using the statement 'import math'.

The math module defines variables 'pi' and 'e' that represent the mathematical constants Pi and Euler's number, respectively. They can be used to perform calculations requiring these values.

To access functions and variables in the math module, you use dot notation. For example, to access the value of pi, you would write 'math.pi'.

A function that returns a specific value after performing its calculations. It uses the 'return' keyword to send back a result.

The expression after the 'return' keyword is the value that will be returned by the function. It can be a simple value or a more complex calculation involving variables or other functions.

A function can return multiple values by listing them after the 'return' keyword, separated by commas. When used in an assignment, you need a separate variable for each returned value.

A short, anonymous function in Python defined using the 'lambda' keyword. It can take any number of arguments, but it can only have one expression. The result of that expression is automatically returned.

A function defined within another function. It can access variables from the outer function, but the outer function cannot access the inner function directly unless it's returned or passed as an argument.

The process of splitting a program into smaller, self-contained units called modules. This improves code organization, making it easier to understand, test, and maintain.

A function that returns a value back to the part of the program that called it. Useful for performing calculations and passing data.