ExcelPython 返回类型不匹配问题

Question

我在用VBA从Excel文件调用一个Python脚本，配合ExcelPython这个工具。这个Python脚本运行得很好，但Excel总是告诉我在某一行出现了类型不匹配的错误：

Function calcCapValue(times As Range, fRates As Range, strike As Range, vol As Range, delta As Double, pv As Range) As Variant

    Set methods = PyModule("PyFunctions", AddPath:=ThisWorkbook.Path)
    Set result = PyCall(methods, "CalculateCapValue", KwArgs:=PyDict("times", times.Value2, "fwdRates", fRates.Value2, "strike", strike.Cells(1, 1).Value2, "flatVol", vol.Cells(1, 1).Value2, "delta", delta, "pv", pv.Cells(1, 1).Value2))

    calcCapValue = PyVar(PyGetItem(result, "res"))   ' <--- TYPE MISMATCH HERE

    Exit Function

End Function

我搞不明白为什么会这样，我是按照这里的示例代码来的：https://sourceforge.net/p/excelpython/wiki/Putting%20it%20all%20together/，还有这里的：http://www.codeproject.com/Articles/639887/Calling-Python-code-from-Excel-with-ExcelPython

但我还是遇到了这个类型不匹配的问题，搞不清楚原因。

这是我的Python脚本：

#imports
import numpy as np
from scipy.stats import norm

#
#   Cap Price Calculation
#
def CalculateCapValue(times, fwdRates, strike, flatVol, delta, pv):

    capPrice = 0;


    #Iterate through each time for caplet price

    for i in range(0, len(times)):

        ifr = float(fwdRates[i][0])
        iti = float(times[i][0])

        d1 = (np.log(ifr/strike)+((flatVol**2)*iti)/2)/(flatVol*np.sqrt(iti))
        d2 = d1 - (flatVol*np.sqrt(iti))
        Nd1 = norm.cdf(d1)
        Nd2 = norm.cdf(d2)

        capPrice += pv*delta*(ifr*Nd1 - strike*Nd2)

    return {"res": capPrice}

谢谢！

Answer 1

在Sourceforge的ExcelPython讨论论坛上回答了这个问题：

http://sourceforge.net/p/excelpython/discussion/general/thread/97f6c1b0/