如何用 Python 寫乾淨的程式碼 - 最佳實踐指南

# Bad example
def calc(x, y):
    return x + y

# Good example
def calculate_total_price(item_price, tax):
    return item_price + tax

# PEP 8 Example
def calculate_discounted_price(price, discount):
    """Calculate the final price after applying the discount."""
    discounted_amount = price * (discount / 100)
    final_price = price - discounted_amount
    return final_price

# Bad example
def process_order(customer, items):
    total_price = 0
    for item in items:
        total_price += item['price']
    if total_price > 100:
        discount = total_price * 0.1
        total_price -= discount
    # Send email
    print(f"Order confirmed for {customer['name']}")
    return total_price

# Good example
def calculate_total_price(items):
    return sum(item['price'] for item in items)

def apply_discount(total_price):
    if total_price > 100:
        return total_price * 0.9
    return total_price

def send_confirmation_email(customer):
    print(f"Order confirmed for {customer['name']}")

def process_order(customer, items):
    total_price = calculate_total_price(items)
    total_price = apply_discount(total_price)
    send_confirmation_email(customer)
    return total_price

# Without list comprehension
squares = []
for x in range(10):
    squares.append(x ** 2)

# With list comprehension
squares = [x ** 2 for x in range(10)]

# Bad example
def calculate_discount(price):
    return price * 0.1  # Discount is hardcoded

# Good example
DISCOUNT_RATE = 0.1

def calculate_discount(price):
    return price * DISCOUNT_RATE

def find_largest_number(numbers):
    """
    Find the largest number in a list.

    Args:
    numbers (list): A list of numbers.

    Returns:
    int: The largest number.
    """
    return max(numbers)

# Bad example
def get_full_name1(first_name, last_name):
    return first_name + " " + last_name

def get_full_name2(first_name, last_name):
    return first_name + " " + last_name

# Good example
def get_full_name(first_name, last_name):
    return first_name + " " + last_name

# Bad example
def divide_numbers(a, b):
    return a / b

# Good example
def divide_numbers(a, b):
    try:
        return a / b
    except ZeroDivisionError:
        return "Error: Cannot divide by zero"

# Old way
name = "Alice"
greeting = "Hello, %s!" % name

# With f-strings
greeting = f"Hello, {name}!"

# Bad example
from math import *

# Good example
from math import sqrt, pi