09 - 代码示例¶

def fibonacci(n):
    """计算斐波那契数列的第n项"""
    if n <= 1:
        return n
    return fibonacci(n-1) + fibonacci(n-2)

# 测试
for i in range(10):
    print(f"F({i}) = {fibonacci(i)}")

def factorial(n):
    """计算n的阶乘"""
    if n == 0:
        return 1
    return n * factorial(n-1)

# 测试
for i in range(6):
    print(f"{i}! = {factorial(i)}")

import os
import json

def read_json_file(filename):
    """读取JSON文件"""
    with open(filename, 'r', encoding='utf-8') as f:
        return json.load(f)  # json.load()从文件读取JSON并转为Python对象

def write_json_file(filename, data):
    """写入JSON文件"""
    with open(filename, 'w', encoding='utf-8') as f:
        json.dump(data, f, ensure_ascii=False, indent=2)  # json.dump()将Python对象序列化为JSON写入文件

# 测试
data = {"name": "张三", "age": 25}
write_json_file("person.json", data)
loaded_data = read_json_file("person.json")
print(loaded_data)

def process_data(data):
    """处理数据"""
    # 过滤数据
    filtered = [item for item in data if item > 0]  # 列表推导式，简洁地从可迭代对象创建新列表

    # 转换数据
    squared = [x**2 for x in filtered]

    # 统计数据
    total = sum(filtered)
    average = total / len(filtered) if filtered else 0

    return {
        "filtered": filtered,
        "squared": squared,
        "total": total,
        "average": average
    }

# 测试
data = [1, 2, 3, 4, 5, -1, 0, 7, 8, 9]
result = process_data(data)
print(result)

# 使用PEP 8命名规范
def calculate_average(numbers):
    """计算平均值"""
    if not numbers:
        return 0
    return sum(numbers) / len(numbers)

# 使用类型注解
def greet(name: str) -> str:
    """打招呼函数"""
    return f"你好，{name}！"

# 使用文档字符串
def divide(a: float, b: float) -> float:
    """
    除法函数

    Args:
        a: 被除数
        b: 除数

    Returns:
        除法结果

    Raises:
        ZeroDivisionError: 当除数为0时
    """
    if b == 0:
        raise ZeroDivisionError("除数不能为零")
    return a / b

def safe_divide(a, b):
    """安全除法，带错误处理"""
    try:
        return a / b
    except ZeroDivisionError:
        print(f"错误：不能除以零")
        return None
    except TypeError as e:
        print(f"错误：{e}")
        return None

# 测试
result1 = safe_divide(10, 2)
result2 = safe_divide(10, 0)
print(f"10 / 2 = {result1}")
print(f"10 / 0 = {result2}")