CI/TST #34131 fixed test_floordiv_axis0_numexpr_path

[OlivierLuG]

xref #34131

• [ x ] passes black pandas
• [ x ] passes git diff upstream/master -u -- "*.py" | flake8 --diff

Test /pandas/tests/frame/test_floordiv_axis0_numexpr_path is slow. It builds a df with 10^6 elements to tests functions floordiv and pow. The number of elements can be reduced with keeping the same min/max values inside the dataframe.

Before/after timeit comparison:

26.6 s ± 1.04 s per loop (mean ± std. dev. of 7 runs, 1 loop each)
37.6 ms ± 3.45 ms per loop (mean ± std. dev. of 7 runs, 10 loops each)

[OlivierLuG]

I did it : green light :-D I had hard time with it !!!

Summary:
The tests are skipped if numexpr is not installed. Otherwise, the entry dataframe is built to construct the minimum of element to reduce the duration of the test.

[jreback]

this is ok, ping on green.

[jreback]

thanks @OlivierLuG