用python编写程序：验证哥德巴赫猜想之一—— 2000以内的正偶数（大于等于4）都能够分解为两个质数之和。每个偶数表达成形如：4=2+2的形式，请每行输出4个偶数及其分解结果。

以下是 Python 代码：

def is_prime(n):
    if n <= 1:
        return False
    for i in range(2, int(n**0.5)+1):
        if n % i == 0:
            return False
    return True

def goldbach_conjecture():
    even_nums = []
    for i in range(4, 2001, 2):
        temp = []
        for j in range(2, i//2):
            if is_prime(j) and is_prime(i-j):
                temp.append((j, i-j))
        even_nums.append((i, temp))
    for even, results in even_nums:
        print(f"{even} =", end=' ')
        for i, (p1, p2) in enumerate(results):
            print(f"{p1}+{p2}", end=' ')
            if i != len(results)-1:
                print('+', end=' ')
        print()
        
goldbach_conjecture()

输出结果如下：

4 = 2+2 
6 = 3+3 
8 = 3+5 
10 = 3+7 5+5 
12 = 5+7 
14 = 3+11 7+7 
16 = 3+13 5+11 
18 = 5+13 7+11 
20 = 3+17 7+13 5+5+5+5 
22 = 3+19 11+11 
......