I have this huge Excel (xls) file that I have to read data from. I tried using the xlrd library, but is pretty slow. I then found out that by converting the Excel file to CSV file manually and reading the CSV file is orders of magnitude faster.
But I cannot ask my client to save the xls as csv manually every time before importing the file. So I thought of converting the file on the fly, before reading it.
Has anyone done any benchmarking as to which procedure is faster:

Open the Excel file with with the xlrd library and save it as CSV file, or
Open the Excel file with win32com library and save it as CSV file?

I am asking because the slowest part is the opening of the file, so if I can get a performance boots from using win32com I would gladly try it.
if you need to read the file frequently, I think it is better to save it as CSV. Otherwise, just read it on the fly. 
for performance issue, I think win32com outperforms. however, considering cross-platform compatibility, I think xlrd is better.
win32com is more powerful. With it, one can handle Excel in all ways (e.g. reading/writing cells or ranges). 
However, if you are seeking a quick file conversion, I think pandas.read_excel also works.
I am using another package xlwings. so I am also interested with a comparison among these packages. 
to my opinion,
I would use pandas.read_excel to for quick file conversion.
If demanding more processing on Excel, I would choose win32com.
XLRD vs Win32 COM performance comparison