Python高级应用探索之元编程和并发编程详解

# 生成器表达式
gen_exp = (x for x in range(1000000) if x % 2 == 0)
# 列表推导式
list_comp = [x for x in range(1000000) if x % 2 == 0]

def calculate():
    result = 0
    for i in range(1000000):
        result += i
    return result

# 使用集合（set）进行快速查找
names = set(['Alice', 'Bob', 'Charlie'])
if 'Alice' in names:
    print('Alice is present')

# 使用字典（dict）进行快速查找和更新
scores = {'Alice': 90, 'Bob': 85, 'Charlie': 95}
if 'Alice' in scores:
    print('Alice's score:', scores['Alice'])

class MyMeta(type):
    def __new__(mcls, name, bases, attrs):
        modified_attrs = {}
        for attr, value in attrs.items():
            if callable(value):
                modified_attrs[attr] = value
            else:
                modified_attrs[attr.upper()] = value
        return super().__new__(mcls, name, bases, modified_attrs)

class MyClass(metaclass=MyMeta):
    def my_method(self):
        print('Hello, World!')

my_object = MyClass()
my_object.MY_METHOD()   # 输出：Hello, World!

def debug_decorator(func):
    def wrapper(*args, **kwargs):
        print(f'Calling function: {func.__name__}')
        result = func(*args, **kwargs)
        print(f'Result: {result}')
        return result
    return wrapper
@debug_decorator
def add(a, b):
    return a + b

print(add(2, 3))   # 输出：Calling function: add，Result: 5

import threading
def task():
    print('Hello, World!')
thread = threading.Thread(target=task)
thread.start()

import multiprocessing
def task():
    print('Hello, World!')
process = multiprocessing.Process(target=task)
process.start()

import asyncio
async def task():
    print('Hello, World!')
asyncio.run(task())