Problem get file info with Curl in Python

Question

I'm using python 2.7 and I need a python script like following. The problem is waiting file download everytime for result if curl time condition is True. I want to get result without waiting file download even if the condition is True. Same curl command run without problem on shell. How should I make a correction or is there a different method?

import os, subprocess
URL = 'http://www.xxxxx/file.zip'
curl="curl -siz yesterday " + URL + " | grep HTTP/ | awk {'print $2'}"
check = subprocess.check_output(curl, shell=True)
print(check)
if "200" in check:
   ....
   ....