定义和调用函数

1def <function_name>():
2    # Function's body

1def welcome_message():
2    """Prints a standard welcome message."""
3    print("Welcome to the System.")
4    print("Initializing modules...")
5
6# The function is defined above, but runs here
7welcome_message()

1def create_greeting(name):
2    """Generates a personalized greeting."""
3    message = f"Hello, {name}! We are glad you're here."
4    print(message)
5
6# Calling the function with different arguments
7create_greeting("Alex")
8create_greeting("Taylor")

1def calculate_area(length, width):
2    """Calculates the area of a rectangle and returns the result."""
3    area = length * width
4    return area
5
6# 1. Call the function and store the returned result in a variable
7pool_area = calculate_area(length=10, width=5)
8
9# 2. Use the result in another calculation
10tile_cost = pool_area * 15
11
12print(f"Pool Area: {pool_area} sq meters")
13print(f"Total tile cost: ${tile_cost}")

1def process_data():
2    result = 20  # Defined inside the function
3    return result
4
5final_output = process_data()
6print(final_output)
7
8# ERROR: 'result' does not exist here!
9print(result)