Problem with timeit

[ast]

Hi

Time measurment with module timeit seems to work with some 
statements but not with some other statements on my computer.

Python version 3.6.3

from timeit import Timer

>>> Timer("'-'.join([str(i) for i in range(10)])").timeit(10000)
0.179271876732912
>>> Timer("'-'.join([str(i) for i in range(10)])").timeit(100000)
1.7445643231192776

It's OK, with 10 more loops I get 10 more execution time.

But with exponentiation, it's a mess

>>> Timer("x=123456**123456").timeit(1)
6.076191311876755e-06
>>> Timer("x=123456**123456").timeit(10)
3.841270313387213e-06

All wrong, the calculation of 123456**123456 is much longer
than 6 microseconds, it takes few seconds, and with 10 loops 
timeit provided a shorter time ...

What happens plz ?