python编程求1!+2!+3!+...+20!的和

可以通过循环和函数来实现：

def factorial(n):
    if n == 0:
        return 1
    else:
        return n * factorial(n-1)

result = 0
for i in range(1, 21):
    result += factorial(i)

print(result)

输出结果为：`2561327494111820313`