Python Functions | Python Exception Handling | Python tutorials

Python functions are blocks of organized, reusable code that perform a specific task. They help break down complex programs into smaller, more manageable pieces, making your code more modular and easier to maintain. Here are some key concepts related to Python functions:

Function Definition:
To create a function, you use the def keyword followed by the function name, a set of parentheses for optional parameters, and a colon. The function code is indented beneath the def statement.

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def my_function():
# Function code here

Function Invocation:
To execute a function, you call it by using its name followed by parentheses. Any required arguments (input values) can be passed within the parentheses.

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my_function() # Calling the function
Return Statement:
Functions can return values using the return statement. This allows them to produce output that can be used elsewhere in your code.

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def add_numbers(x, y):
result = x + y
return result
Parameters and Arguments:
Parameters are placeholders in a function's definition, while arguments are the actual values passed to a function. You can define functions with parameters to accept input.

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def greet(name):
print(f"Hello, {name}!")

greet("Alice") # "Alice" is the argument
Default Arguments:
You can assign default values to parameters, making them optional. If a value is not provided, the default is used.

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def greet(name="Guest"):
print(f"Hello, {name}!")

greet() # "Guest" is used as the default
greet("Alice") # "Alice" overrides the default
Variable Scope:
Variables defined inside a function have local scope, which means they are only accessible within that function. Variables defined outside of functions have global scope and can be accessed throughout the program.

Docstrings:
It's good practice to include a docstring at the beginning of a function to document what the function does, what parameters it accepts, and what it returns.

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def add_numbers(x, y):
"""
Adds two numbers together.

Args:
x (int): The first number.
y (int): The second number.

Returns:
int: The sum of x and y.
"""
result = x + y
return result
Lambda Functions:
Lambda functions, also known as anonymous functions, are small, one-line functions defined using the lambda keyword. They are often used for simple operations and can be passed as arguments to other functions.

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square = lambda x: x ** 2
Function Recursion:
Functions can call themselves, a concept known as recursion. It's a powerful technique for solving problems that can be broken down into smaller, similar sub-problems.

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def factorial(n):
if n == 1:
return 1
else:
return n * factorial(n - 1)
Built-in Functions:
Python comes with a wide range of built-in functions, such as print(), len(), max(), and min(), which you can use without defining them.

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print("Hello, World!")
length = len([1, 2, 3, 4])
Functions are fundamental to writing structured and modular Python code. They help improve code readability, reusability, and maintainability. You can define your own functions to solve specific problems or use existing libraries of functions to perform various tasks.

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