面试题：Python正则匹配多个字符串的复杂场景处理

Question

给定一个包含多种编程语言介绍的长文本字符串，例如 'C++ is a powerful language for system programming. Python is popular for data analysis. JavaScript is used for web front - end. Ruby has its own unique features.'，要求使用Python正则表达式找出所有编程语言名称（假设编程语言名称以首字母大写开头，且后面紧跟字母），并统计每种编程语言出现的次数，最后以字典形式输出结果，例如 {'C++': 1, 'Python': 1, 'JavaScript': 1, 'Ruby': 1}。

Answer 1

import re

text = 'C++ is a powerful language for system programming. Python is popular for data analysis. JavaScript is used for web front - end. Ruby has its own unique features.'
pattern = r'\b[A-Z][a-zA-Z]+\b'
languages = re.findall(pattern, text)
result = {}
for lang in languages:
    if lang not in result:
        result[lang] = 1
    else:
        result[lang] += 1

print(result)