How to know the folder size in a zipfile

I know that you can get the size in bytes of a file in a ZIP file using the .file_size method But is there any what I can get the size of a folder instead?

Ex:

import zipfile, os

os.chdir('C:\')    
zp= zipfile.ZipFile('example.zip')

spamInfo = zp.getinfo('spam.txt')    #Here, Instead of a file I'd like to put a folder
spamInfo.file_size

zp.close()

Answer

import zipfile

zp = zipfile.ZipFile("example.zip")

size = sum([zinfo.file_size for zinfo in zp.filelist])
zip_kb = float(size) / 1000  # kB