python读取单元格公式计算结果,使用python xlrd从Excel单元格获取公式

I have to port an algorithm from an Excel sheet to python code but I have to reverse engineer the algorithm from the Excel file.

The Excel sheet is quite complicated, it contains many cells in which there are formulas that refer to other cells (that can also contains a formula or a constant).

My idea is to analyze with a python script the sheet building a sort of table of dependencies between cells, that is:

A1 depends on B4,C5,E7 formula: "=sqrt(B4)+C5*E7"

A2 depends on B5,C6 formula: "=sin(B5)*C6"

...

The xlrd python module allows to read an XLS workbook but at the moment I can access to the value of a cell, not the formula.

For example, with the following code I can get simply the value of a cell:

import xlrd

#open the .xls file

xlsname="test.xls"

book = xlrd.ope