超越基础：掌握 Python 的隐藏功能以实现高效编码

x, y = 5, 10x, y = y, xprint(x, y)  # output: 10, 5

def greet(name, age):    print(f"hello, {name}! you are {age} years old.")info = {"name": "alice", "age": 30}greet(**info)  # output: hello, alice! you are 30 years old.

a, *b, c = [1, 2, 3, 4, 5]print(a, b, c)  # output: 1 [2, 3, 4] 5

squares = [x**2 for x in range(10) if x % 2 == 0]print(squares)  # output: [0, 4, 16, 36, 64]

matrix = [[1, 2, 3], [4, 5, 6], [7, 8, 9]]flat = [num for row in matrix for num in row]print(flat)  # output: [1, 2, 3, 4, 5, 6, 7, 8, 9]

from collections import defaultdictd = defaultdict(int)d['a'] += 1print(d)  # output: defaultdict(<class 'int'>, {'a': 1})

from collections import counterwords = ["apple", "banana", "apple", "orange", "banana", "apple"]count = counter(words)print(count)  # output: counter({'apple': 3, 'banana': 2, 'orange': 1})

from collections import dequequeue = deque([1, 2, 3])queue.append(4)queue.popleft()print(queue)  # output: deque([2, 3, 4])

class lazy:    def __init__(self):        self.data = {}    def __getattr__(self, name):        if name not in self.data:            self.data[name] = f"value for {name}"        return self.data[name]obj = lazy()print(obj.foo)  # output: value for foo

def infinite_counter():    count = 0    while true:        yield count        count += 1counter = infinite_counter()print(next(counter))  # output: 0print(next(counter))  # output: 1

def numbers():    for i in range(10):        yield idef squared(seq):    for num in seq:        yield num**2pipeline = squared(numbers())print(list(pipeline))  # Output: [0, 1, 4, 9, 16, 25, 36, 49, 64, 81]