求！！代码！！！！！

i = 0   
total = 0
signal = 1
next_one = 1 / (2* i + 1) * signal  # 下一项的值

while abs(next_one) > 10 ** (-5):   # 当绝对值大于阈值，继续计算
    total += next_one
    signal *= (-1)             # 每项的正负，交替变化
    i += 1
    next_one = 1 / (2* i + 1) * signal   # 预先计算下一项的值

print(total, 3.141675 / 4)   # 0.7853931633974454 0.78541875

通过结果可以看到非常相近