df[[0,4]]
将允许选择索引0和4。
自从
take
已弃用,与您建议的代码等效的是使用
gather
:
df.select(pl.all().gather([0, 4]))
输出
shape: (2, 3)
âââââââââââ¬ââââââââââââââââââââââ¬ââââââââ
â integer â date â float â
â --- â --- â --- â
â i64 â datetime[μs] â f64 â
âââââââââââªââââââââââââââââââââââªââââââââ¡
â 1 â 2022-01-01 00:00:00 â 4.0 â
â 5 â 2022-01-05 00:00:00 â 8.0 â
âââââââââââ´ââââââââââââââââââââââ´ââââââââ
500k行的计时:
# df.select(pl.all().gather([0, 4]))
145 µs ± 9.43 µs per loop (mean ± std. dev. of 7 runs, 10,000 loops each)
# df[[0,4]]
122 µs ± 14.3 µs per loop (mean ± std. dev. of 7 runs, 10,000 loops each)
5M行的计时:
# df.select(pl.all().gather([0, 4]))
150 µs ± 13.3 µs per loop (mean ± std. dev. of 7 runs, 10,000 loops each)
# df[[0,4]]
117 µs ± 17.7 µs per loop (mean ± std. dev. of 7 runs, 10,000 loops each)