Python 3.11: What changed in math?

Introduces what's new in the math module in Python 3.11.

Transcript

1. Kimikazu Kato Python 3.11 What changed in math? PyCon JP 2022 LT in party
2. About myself Kimikazu Kato Ճ౻ެҰ Data scientist at Softbank Corp. Twitter: @hamukazu
3. About our service Axross Recipe Leaning site for machine learning and data analysis User create contents, but high quality (created by professional data scientists) ݸਓͰ΋๏ਓͰ΋ར༻Ͱ͖·͢ʂ https://axross-recipe.com/
4. What chaged in math? https://docs.python.org/3.11/whatsnew/3.11.html
6. math.exp2(): return 2 raised to the power of x. math.cbrt(): return the cube root of x. Do we really need them? They can be computed using existing functions. 2x 3 x
7. Reasons • Implemented in C99 • Also implemented in numpy • For better accuracy
8. Accuracy >>> 5**(1/3) 1.7099759466766968 >>> pow(5,1/3) 1.7099759466766968 >>> math.cbrt(5) 1.709975946676697 Di ff erent results!
9. Performance >>> timeit.timeit("2**1.2", "import math") 0.013247291004518047 >>> timeit.timeit("math.exp2(1.2)", "import math") 0.04908258400973864 >>> timeit.timeit("5**(1/3)","import math") 0.012019957997836173 >>> timeit.timeit("math.cbrt(5)","import math") 0.06318095800816081 Slower! (I don't know why)
11. Mathematically is not de fi ned, but lim x→−∞ ax = lim x→∞ 1 ax = ∞ for 0−∞ |a| < 1, a ≠ 0 Thus this is reasonable.
12. ax a > 0 x can be de fi ned for an arbitrary if a < 0 ax For , is only de fi ned if is integer x 0x = 0 if unde fi ned if unde fi ned also for but it is sometimes convenient to de fi ne x < 0 x > 0 x = 0 00 = 1 Mathematical de fi nition of power operation ax (Caution: sometimes di ff erent from computer implementation)
13. \lim_{x\to -\infty} a^x
14. The math.nan is already implemented in the past, but has not been available for all the environments (??) Before 3.11, the common way to get nan is float("nan")
15. Conclusion • The math module is still improving! • Don't forget about math! Numpy is not everything!
16. Thank You https://axross-recipe.com/