TypeError：当将整数与整数列表相乘时，不能将序列乘以“浮点”类型的非整数

Question

我的代码：

import numpy as np
import sympy as sym

df = [0.99833714, 0.96852   , 0.95101663, 0.92618755]
mat = list(np.arange(1,5)/2)

def task2(df,mat,comp):
    """
    inputs:
    df - list with discount factors
    mat - list with respective maturities
    comp - either a positive integer for compounding frequency per year or 0 for continuous compounding
    returns: numpy array with spot rates (in decimals p.a.) in the same order as inputs
    """
    
    if comp > 0:
        rate = comp*([x for x in df]**(-1/comp*[y for y in mat])-1)
    else:
        rate = -(1/[y for y in mat])*np.log([x for x in df])
    
    rate.asarray()
    
    return rate

这是我在玩 task2() 时遇到的错误，我不明白为什么会产生错误，而且我在 StackOverflow 或其他地方找不到任何相关内容：

---------------------------------------------------------------------------
TypeError                                 Traceback (most recent call last)
<ipython-input-102-430bc9fc5d7f> in <module>
----> 1 print(task2(df,mat,2))
      2 print(task2(df,mat,0))

<ipython-input-100-5b721054deb4> in task2(df, mat, comp)
     16 
     17     if comp > 0:
---> 18         rate = comp*([x for x in df]**(-1/comp*[y for y in mat])-1)
     19     else:
     20         rate = -(1/[y for y in mat])*np.log([x for x in df])

TypeError: can't multiply sequence by non-int of type 'float'

如果 `comp 肯定是整数，谁能告诉我为什么会出现这个错误？

Answer 1

在下面的代码部分中，-1/comp 将导致浮点数，除非 comp 为 1 或者您使用的是 Python 2。

(-1/comp*[y for y in mat])