Python 30段代码提升开发效率，高效实用

defremove_duplicates(lst):
    seen = set()
    return [xforxinlstifnot (xinseenorseen.add(x))]

# 示例
original = [3, 2, 1, 2, 3, 4, 5, 4]
result = remove_duplicates(original)
print(result)  # [3, 2, 1, 4, 5]

defreverse_dict(d):
    return {v: kfork, vind.items()}

# 示例
original = {'a': 1, 'b': 2, 'c': 3}
reversed_dict = reverse_dict(original)
print(reversed_dict)  # {1: 'a', 2: 'b', 3: 'c'}

fromcollectionsimportCounter

data = ['apple', 'banana', 'apple', 'orange', 'banana', 'apple']
freq = Counter(data)
print(freq.most_common(2))  # [('apple', 3), ('banana', 2)]

defis_number(s):
    try:
        float(s)
        returnTrue
    exceptValueError:
        returnFalse

# 示例
print(is_number("123.45"))  # True
print(is_number("abc"))     # False

importrandom
importstring

defrandom_string(length=8):
    chars = string.ascii_letters+string.digits
    return''.join(random.choice(chars) for_inrange(length))

# 示例
print(random_string(10))  # 类似 "aB3dE7gH9j"

defcapitalize_words(s):
    return' '.join(word.capitalize() forwordins.split())

# 示例
text = "hello world python"
print(capitalize_words(text))  # "Hello World Python"

defcount_lines(filename):
    withopen(filename, 'r', encoding='utf-8') asf:
        returnsum(1for_inf)

# 示例
line_count = count_lines('data.txt')
print(f"文件共有 {line_count} 行")

importos

defbatch_rename(folder, prefix):
    fori, filenameinenumerate(os.listdir(folder), 1):
        old_path = os.path.join(folder, filename)
        new_name = f"{prefix}_{i}{os.path.splitext(filename)[1]}"
        new_path = os.path.join(folder, new_name)
        os.rename(old_path, new_path)

fromdatetimeimportdatetime

defdays_between(date1, date2):
    d1 = datetime.strptime(date1, "%Y-%m-%d")
    d2 = datetime.strptime(date2, "%Y-%m-%d")
    returnabs((d2-d1).days)

# 示例
days = days_between("2024-01-01", "2024-03-20")
print(f"相差 {days} 天")

importtime

timestamp = int(time.time())
print(f"当前时间戳: {timestamp}")

importrequests

deffetch_url(url):
    try:
        response = requests.get(url, timeout=5)
        returnresponse.status_code, response.text[:100]
    exceptrequests.RequestExceptionase:
        returnNone, str(e)

# 示例
status, content = fetch_url("https://httpbin.org/get")
print(f"状态码: {status}")

fromfunctoolsimportlru_cache

@lru_cache(maxsize=None)
deffibonacci(n):
    ifn<2:
        returnn
    returnfibonacci(n-1) +fibonacci(n-2)

# 示例
print(fibonacci(10))  # 55

defquick_sort(arr):
    iflen(arr) <= 1:
        returnarr
    pivot = arr[len(arr)//2]
    left = [xforxinarrifx<pivot]
    middle = [xforxinarrifx == pivot]
    right = [xforxinarrifx>pivot]
    returnquick_sort(left) +middle+quick_sort(right)

# 示例
data = [3, 6, 8, 10, 1, 2, 1]
sorted_data = quick_sort(data)
print(sorted_data)  # [1, 1, 2, 3, 6, 8, 10]

defprogress_bar(iteration, total, length=50):
    percent = (iteration/total)
    filled_length = int(length*percent)
    bar = '█'*filled_length+'-'* (length-filled_length)
    print(f'\r|{bar}| {percent:.1%}', end='\r')
    ifiteration == total:
        print()

# 示例
total_items = 100
foriinrange(total_items+1):
    progress_bar(i, total_items)
    time.sleep(0.01)

importsys

defmemory_usage(obj):
    returnsys.getsizeof(obj)

# 示例
data_list = [iforiinrange(1000)]
print(f"列表占用内存: {memory_usage(data_list)} 字节")

importre

defis_valid_email(email):
    pattern = r'^[a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,}$'
    returnbool(re.match(pattern, email))

# 示例
print(is_valid_email("test@example.com"))  # True
print(is_valid_email("invalid-email"))     # False

defcheck_password_strength(password):
    iflen(password) <8:
        return"弱"
    has_upper = any(c.isupper() forcinpassword)
    has_lower = any(c.islower() forcinpassword)
    has_digit = any(c.isdigit() forcinpassword)
    has_special = any(notc.isalnum() forcinpassword)
    
    score = sum([has_upper, has_lower, has_digit, has_special])
    ifscore == 4:
        return"强"
    elifscore>= 2:
        return"中"
    else:
        return"弱"

importthreading
importtime

defworker(name, delay):
    print(f"线程 {name} 开始")
    time.sleep(delay)
    print(f"线程 {name} 结束")

# 示例
threads = []
foriinrange(3):
    t = threading.Thread(target=worker, args=(f"Thread-{i}", i+1))
    threads.append(t)
    t.start()

fortinthreads:
    t.join()

defhandle_errors(func):
    defwrapper(*args, **kwargs):
        try:
            returnfunc(*args, **kwargs)
        exceptExceptionase:
            print(f"错误发生: {type(e).__name__}: {e}")
            returnNone
    returnwrapper

@handle_errors
defrisky_operation(x, y):
    returnx/y

# 示例
result = risky_operation(10, 0)  # 输出: 错误发生: ZeroDivisionError: division by zero

importjson

defsave_to_json(data, filename):
    withopen(filename, 'w', encoding='utf-8') asf:
        json.dump(data, f, ensure_ascii=False, indent=2)

defload_from_json(filename):
    withopen(filename, 'r', encoding='utf-8') asf:
        returnjson.load(f)

# 示例
data = {"name": "张三", "age": 25, "skills": ["Python", "Java"]}
save_to_json(data, "user.json")
loaded_data = load_from_json("user.json")
print(loaded_data)

defis_prime(n):
    ifn<2:
        returnFalse
    foriinrange(2, int(n**0.5) +1):
        ifn%i == 0:
            returnFalse
    returnTrue

# 示例
print(is_prime(17))  # True
print(is_prime(20))  # False

defgcd(a, b):
    whileb:
        a, b = b, a%b
    returna

# 示例
print(gcd(48, 18))  # 6

defmixed_string_length(s):
    chinese_count = sum(1forcinsif'\u4e00'<= c<= '\u9fff')
    english_count = len(s) -chinese_count
    returnchinese_count*2+english_count

# 示例
text = "Hello世界Python编程"
print(f"混合长度: {mixed_string_length(text)}")  # 20

importplatform

defsystem_info():
    info = {
        "系统": platform.system(),
        "版本": platform.version(),
        "处理器": platform.processor(),
        "Python版本": platform.python_version()
    }
    returninfo

# 示例
print(system_info())

fromPILimportImage

defget_image_size(image_path):
    withImage.open(image_path) asimg:
        returnimg.size

# 示例
width, height = get_image_size("example.jpg")
print(f"图片尺寸: {width}x{height}")

importsqlite3

defcreate_db():
    conn = sqlite3.connect('example.db')
    cursor = conn.cursor()
    cursor.execute('''CREATE TABLE IF NOT EXISTS users
                     (id INTEGER PRIMARY KEY, name TEXT, age INTEGER)''')
    conn.commit()
    conn.close()

importre

defextract_urls(text):
    pattern = r'https?://[^\s<>"]+|www\.[^\s<>"]+'
    returnre.findall(pattern, text)

# 示例
html = '访问 <a href="https://www.example.com">示例网站</a> 和 http://test.com'
urls = extract_urls(html)
print(urls)  # ['https://www.example.com', 'http://test.com']

importzipfile

defzip_files(files, zipname):
    withzipfile.ZipFile(zipname, 'w') aszipf:
        forfileinfiles:
            zipf.write(file)

defunzip_file(zipname, extract_to):
    withzipfile.ZipFile(zipname, 'r') aszipf:
        zipf.extractall(extract_to)

importtime

deftimer(func):
    defwrapper(*args, **kwargs):
        start = time.perf_counter()
        result = func(*args, **kwargs)
        end = time.perf_counter()
        print(f"{func.__name__} 执行时间: {end - start:.6f}秒")
        returnresult
    returnwrapper

@timer
defslow_function():
    time.sleep(1)
    return"完成"

# 示例
slow_function()

defnormalize_data(data):
    min_val = min(data)
    max_val = max(data)
    return [(x-min_val) / (max_val-min_val) forxindata]

# 示例
original = [10, 20, 30, 40, 50]
normalized = normalize_data(original)
print(normalized)  # [0.0, 0.25, 0.5, 0.75, 1.0]