Tupling a generator vs. list comping

ipython-pypy-1.9.out

pypy-1.9 Python 2.7.2

In [1]: g = xrange(10000)

In [2]: %timeit tuple(i for i in g)
1000 loops, best of 3: 659 us per loop

In [3]: %timeit [i for i in g]
10000 loops, best of 3: 77.9 us per loop

In [4]: g = xrange(1000000)

In [5]: %timeit tuple(i for i in g)
1 loops, best of 3: 211 ms per loop

In [6]: %timeit [i for i in g]
10 loops, best of 3: 22.8 ms per loop

ipython-python-2.6.6.out

CPython Python 2.6.6

In [13]: g = xrange(1000)

In [14]: %timeit tuple(i for i in g)
10000 loops, best of 3: 79.9 us per loop

In [15]: %timeit [i for i in g]
10000 loops, best of 3: 60.2 us per loop

In [16]: g = xrange(10000)

In [17]: %timeit tuple(i for i in g)
1000 loops, best of 3: 782 us per loop

In [18]: %timeit [i for i in g]
1000 loops, best of 3: 589 us per loop

In [19]: g = xrange(1000000)

In [20]: %timeit tuple(i for i in g)
10 loops, best of 3: 93.4 ms per loop

In [21]: %timeit [i for i in g]
10 loops, best of 3: 78.1 ms per loop

This is for stock Python 2.6.