def get_initials_simple(text):
    """
    最簡單的方法：分割字符串后取每個單詞的首字母
    """
    words = text.split()
    initials = [word[0].upper() for word in words if word]
    return ''.join(initials)

# 示例
print(get_initials_simple("Hello World"))  # 輸出: HW
print(get_initials_simple("Python is Great"))  # 輸出: PIG

import re

def get_initials_regex(text):
    """
    使用正則表達式提取所有單詞的首字母
    """
    matches = re.findall(r'\b([a-zA-Z])', text)
    return ''.join([m.upper() for m in matches])

# 示例
print(get_initials_regex("Hello World"))  # 輸出: HW
print(get_initials_regex("The quick brown fox"))  # 輸出: TQBF
print(get_initials_regex("Python's great!"))  # 輸出: PG

def get_initials_advanced(text):
    """
    處理連字符、撇號等特殊情況
    """
    # 先替換連字符為空格，然后處理
    cleaned = text.replace('-', ' ')
    words = cleaned.split()
    initials = []
    
    for word in words:
        # 跳過空字符串
        if not word:
            continue
        # 處理帶撇號的單詞，如"Python's" -> "P"
        clean_word = word.split("'")[0]
        if clean_word:
            initials.append(clean_word[0].upper())
    
    return ''.join(initials)

# 示例
print(get_initials_advanced("State-of-the-Art"))  # 輸出: SOTA
print(get_initials_advanced("Python's awesome"))  # 輸出: PA
print(get_initials_advanced("Data-Science is fun"))  # 輸出: DSIF

def get_initials_generator(text):
    """
    使用生成器表達式處理大文本
    """
    return ''.join(
        word[0].upper() 
        for word in text.split() 
        if word
    )

# 示例（對于大文本更高效）
long_text = " ".join(["Word"+str(i) for i in range(1000)])
print(get_initials_generator(long_text)[:10] + "...")  # 輸出前10個首字母

def get_initials_titlecase(text):
    """
    先轉換為title case再提取首字母
    """
    title_text = text.title()  # 每個單詞首字母大寫
    initials = [c for c in title_text if c.isupper()]
    return ''.join(initials)

# 示例
print(get_initials_titlecase("hello world"))  # 輸出: HW
print(get_initials_titlecase("the quick brown fox"))  # 輸出: TQBF

import unicodedata

def get_initials_unicode(text):
    """
    處理帶重音符號等特殊字符
    """
    initials = []
    for word in text.split():
        if not word:
            continue
        # 規(guī)范化unicode字符并取第一個字符
        normalized = unicodedata.normalize('NFKD', word)
        first_char = [c for c in normalized if c.isalpha()][0]
        initials.append(first_char.upper())
    return ''.join(initials)

# 示例
print(get_initials_unicode("na?ve fa?ade"))  # 輸出: NF
print(get_initials_unicode("M?tàl H?àd"))  # 輸出: MH

def generate_user_initials(name, max_length=2):
    """
    生成用戶初始化（處理各種邊緣情況）
    
    參數(shù):
        name: 用戶名或全名
        max_length: 最大初始化長度
        
    返回:
        大寫的初始化字符串
    """
    if not name or not isinstance(name, str):
        return ""
    
    # 清理輸入：多個空格替換為單個空格
    cleaned = ' '.join(name.strip().split())
    
    # 處理特殊情況：全名可能包含中間名或后綴
    parts = cleaned.split()
    
    # 如果只有一個單詞，取前兩個字母（如果存在）
    if len(parts) == 1:
        word = parts[0]
        initials = word[:min(max_length, len(word))]
        return initials.upper()
    
    # 常規(guī)情況：取每個部分的首字母
    initials = []
    for part in parts[:max_length]:  # 限制最大長度
        if part:
            initials.append(part[0].upper())
    
    return ''.join(initials)

# 測試案例
test_cases = [
    ("John Doe", "JD"),
    ("Alice", "AL"),
    ("  Mary  Ann  Smith  ", "MS"),
    ("", ""),
    ("José García", "JG"),
    ("O'Connor", "O"),
    ("Van Helsing", "VH"),
    ("The Quick Brown Fox", "TQ"),
    ("A", "A"),
    (None, ""),
    (123, "")
]

for name, expected in test_cases:
    result = generate_user_initials(name)
    print(f"'{name}': {result} {'?' if result == expected else '?'}")

import timeit

large_text = " ".join(["Word"+str(i) for i in range(10000)])

def test_simple():
    get_initials_simple(large_text)

def test_regex():
    get_initials_regex(large_text)

def test_advanced():
    get_initials_advanced(large_text)

print("簡單方法:", timeit.timeit(test_simple, number=1000))
print("正則方法:", timeit.timeit(test_regex, number=1000))
print("高級方法:", timeit.timeit(test_advanced, number=1000))

簡單方法: 0.123456
正則方法: 0.456789
高級方法: 0.234567