You can't do it without blocking or threading unless you are willing to lose precision...

I'd suggest sometime like this, but threading is the correct way to do this...

import time

counter = 31
start = time.time()
while True:
    ### Do other stuff, it won't be blocked
    time.sleep(0.1)
    print "looping..."

    ### When 1 sec or more has elapsed...
    if time.time() - start > 1:
        start = time.time()
        counter = counter - 1

        ### This will be updated once per second
        print "%s seconds remaining" % counter

        ### Countdown finished, ending loop
        if counter <= 0:
            break

or even...

import time

max = 31
start = time.time()
while True:
    ### Do other stuff, it won't be blocked
    time.sleep(0.1)
    print "looping..."

    ### This will be updated every loop
    remaining = max + start - time.time()
    print "%s seconds remaining" % int(remaining)

    ### Countdown finished, ending loop
    if remaining <= 0:
        break

Use sleep() from the time module. It can take a float argument for sub-second resolution.

from time import sleep
sleep(0.1)  # Time in seconds

You could use threading.Timer:

from __future__ import print_function
from threading import Timer

def func1():
    func2()
    print("Do stuff here")
def func2():
    Timer(10, print, ["Do more stuff here"]).start()

func1()

But as @unholysampler already pointed out it might be better to just write:

import time

def func1():
    print("Do stuff here")
    func2()

def func2():
    time.sleep(10)
    print("Do more stuff here")

func1()