这有记录在案吗?为什么会有如此巨大的差异?
# Python 3.2
# numpy 1.6.2 using Intel's Math Kernel Library
>>> import numpy as np
>>> x = np.float64(-0.2)
>>> x ** 0.8
__main__:1: RuntimeWarning: invalid value encountered in double_scalars
nan
>>> x = -0.2 # note: `np.float` is same
我正在用Python编写一个计算器,并且正在处理指数运算。在处理十进制指数时,我遇到了一些非常奇怪的问题,所以我尝试在控制台中重现这个问题。这是我得到的: Python 3.5.2 (default, Oct 11 2016, 04:59:56)
[GCC 4.2.1 Compatible Apple LLVM 8.0.0 (clang-800.0.38)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>
我在处理CS50的信贷问题。我在找这个数字的倒数第二位。例如,4003600000000014.It应为4,0,6,0,0,0,0,1。我被这个循环搞糊涂了。当我使用数字,例如1,2,...15来代替2i-1时,它起作用了。但在这个循环中,它不起作用。它给了我6,6,6,6,6,6,6,6谢谢你的帮助! ` long answer=get_long("Number: ");
int i;
long a;
for (i=1; i<9 ; i++)
{
a= fmod((answer / (pow(10,2i-1))),10);
printf("%
在python文档中,它是为内置函数complex([realimag])编写的:
..or convert a string or number to a complex number.
但当我尝试时:
>>> complex('string')
我得到了:
Traceback (most recent call last):
File "<interactive input>", line 1, in <module>
ValueError: complex() arg is a malformed st
我正在使用Python 3.6。
我真的很困惑,为什么会发生这样的事情?
In [1]: import numpy as np
In [2]: a = np.array(-1)
In [3]: a
Out[3]: array(-1)
In [4]: a ** (1/3)
/Users/wonderful/anaconda/bin/ipython:1: RuntimeWarning: invalid value encountered in power
#!/Users/wonderful/anaconda/bin/python
Out[4]: nan
class Complex
{
public:
Complex(float = 0.0, float = 0.0); //default constructor that uses default arg. in case no init. are in main
void getComplex(); //get real and imaginary numbers from keyboard
void sum(Complex, Complex); //method to add two complex numbers together
void diff(Complex, C
我还是不明白。如果我将Accept-Language头设置为"en“(de,pl,es)以外的任何东西,甚至是不存在的东西(如xxs),则应用程序不会抛出此错误,但当我将其设置为"en”时也会这样做。它只发生在windows (最新的gettext工具)上。下面是堆栈跟踪:
Traceback (most recent call last):
File "E:\projekty\python\myapp_api\_env\lib\site-packages\django\core\han
dlers\exception.py", line 39, in in