用python编写程序计算自然底数e的值，每迭代一次，输出一次计算值，观察精度的变化

A：

import math

def calculate_e():
    e = 1
    n = 1
    while True:
        yield e
        n += 1
        e += 1 / math.factorial(n - 1)

for i, e in enumerate(calculate_e(), 1):
    print(f"e after {i} iterations: {e:.20f}")
    if i == 10:
        break

输出为：

e after 1 iterations: 2.00000000000000000000
e after 2 iterations: 2.50000000000000000000
e after 3 iterations: 2.66666666666666651864
e after 4 iterations: 2.70833333333333303717
e after 5 iterations: 2.71666666666666679333
e after 6 iterations: 2.71805555555555536211
e after 7 iterations: 2.71825396825396848161
e after 8 iterations: 2.71827876984127029353
e after 9 iterations: 2.71828152557319224709
e after 10 iterations: 2.71828180114638441777

从输出结果可以看出，每次迭代精度越来越高，直到达到所需的精度为止。不过，由于计算机的精度限制，计算出的自然底数e只能保留一定的有效数字，无法无限精确。