Is there a performance cost putting python imports inside functions?

Question

I build quite complex python apps, often with Django. To simplify inter-application interfaces I sometimes use service.py modules that abstract away from the models.

As

Answer 1

As ray said, importing specific functions is (slightly faster) 1.62852311134 for sin() 1.89815092087 for math.sin() using the following code

from time import time
sin=math.sin
t1=time()
for i in xrange(10000000):
x=sin(i)
t2=time()
for i in xrange(10000000):
    z=math.sin(i)
t3=time()
print (t2-t1)
print (t3-t2)