有時(shí)候需要比較大的計(jì)算量,這個(gè)時(shí)候Python的效率就很讓人捉急了,此時(shí)可以考慮使用numba 進(jìn)行加速,效果提升明顯~
(numba 安裝貌似很是繁瑣,建議安裝Anaconda,里面自帶安裝好各種常用科學(xué)計(jì)算庫)
from numba import jit@jitdef t(count=1000): total = 0 for i in range(int(count)): total += i return total
測試效果:
(關(guān)于__wrapped__ 見我的博文: 淺談解除裝飾器作用(python3新增) )
In [17]: %timeit -n 1 t.__wrapped__()1 loop, best of 3: 52.9 µs per loopIn [18]: %timeit -n 1 t()The slowest run took 13.00 times longer than the fastest. This could mean that an intermediate result is being cached.1 loop, best of 3: 395 ns per loop
可以看到使用jit 加速后,即使設(shè)置測試一次,實(shí)際上還是取了三次的最優(yōu)值,如果取最壞值(因?yàn)樽顑?yōu)值可能是緩存下來的),則耗時(shí)為395ns * 13 大概是5us 還是比不使用的52.9us 快上大概10倍,
增大計(jì)算量可以看到使用numba加速后的效果提升更加明顯,
In [19]: %timeit -n 10 t.__wrapped__(1e6)10 loops, best of 3: 76.2 ms per loopIn [20]: %timeit -n 1 t(1e6)The slowest run took 8.00 times longer than the fastest. This could mean that an intermediate result is being cached.1 loop, best of 3: 790 ns per loop
如果減少計(jì)算量,可以看到當(dāng)降到明顯小值時(shí),使用加速后的效果(以最差計(jì))與不加速效果差距不大,因此如果涉及到較大計(jì)算量不妨使用jit 加速下,何況使用起來這么簡便。
%timeit -n 1 t(10)1 loop, best of 3: 0 ns per loop%timeit -n 100 t.__wrapped__(10)100 loops, best of 3: 1.79 µs per loop%timeit -n 1 t(1)The slowest run took 17.00 times longer than the fastest. This could mean that an intermediate result is being cached.1 loop, best of 3: 395 ns per loop%timeit -n 100 t.__wrapped__(1)100 loops, best of 3: 671 ns per loop
以上這篇使用numba對Python運(yùn)算加速的方法就是小編分享給大家的全部內(nèi)容了,希望能給大家一個(gè)參考,也希望大家多多支持武林站長站。
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