一般数字Python问题 [英] General Numerical Python question

问题描述

一般来说，如果有一个列表（来自常规Python）和一个

数组（来自Numerical Python），它包含相同数量的

元素，那么循环或For循环处理它们的速度是否相同？b $ b？或者，阵列处理速度会更快吗？


我是Python的新手，所以我的问题可能会暴露我的无知。我赞赏任何人帮助我理解的努力。


谢谢。非常感谢。


Matt

解决方案

2mc写道：

一般来说，如果有一个列表（来自常规Python）和一个
数组（来自Numerical Python）包含相同数量的
元素，那么While循环或For循环过程他们以同样的速度？或者，数组处理速度会更快吗？

我是Python的新手，所以我的问题可能会暴露我的无知。我很欣赏任何人帮助我理解的努力。

我不知道，我从未测量过。让我们一起来看看。


回答这些性能问题的最好方法，根据您的平台和确切版本，这可能很容易因为b $ b而变化很小

涉及，是_measure_。 Python 2.3的标准库附带了

timeit.py，这是一个专为此而制作的小脚本。我把它复制到了我的

~ / bin /目录并完成了一个chmod + x（从一个shebang行开始

这样就足够了），或者在Windows中，您可以设置.bat或.cmd

文件来调用Python。无论如何，它很容易使用：你指定零

或更多-s''blahblah''参数设置，然后是你想要的特定

语句时间。观看......：


[alex @ lancelot pop]

timeit.py -s''import数字''-s''x = Numeric.arange（555）''

''for x in x：id（i）''

1000循环，最佳3：296 usec每循环

[alex @ lancelot pop]

timeit.py -s''import数字''-s''x =范围（555）''''我在

x：id（i）''

1000循环，最佳3：212每循环usec

[alex @ lancelot pop]

Generally speaking, if one had a list (from regular Python) and an
array (from Numerical Python) that contained the same number of
elements, would a While loop or a For loop process them at the same
speed? Or, would the array process faster?

I''m new to Python, so my question may expose my ignorance. I
appreciate anyone''s effort to help me understand.

Thanks. It is much appreciated.

Matt

解决方案

2mc wrote:

Generally speaking, if one had a list (from regular Python) and an
array (from Numerical Python) that contained the same number of
elements, would a While loop or a For loop process them at the same
speed? Or, would the array process faster?

I''m new to Python, so my question may expose my ignorance. I
appreciate anyone''s effort to help me understand.

I don''t know, I''ve never measured. Let''s find out together.

The best way to answer these performance questions, which may
easily vary a little depending on your platform and exact versions
involved, is to _measure_. Python 2.3''s standard library comes with
timeit.py, a little script that''s made just for that. I''ve copied it to my
~/bin/ directory and done a chmod +x (it starts with a shebang line
so that''s sufficient), or in Windows you might set up a .bat or .cmd
file to call Python on it. Anyway, it''s easy to use: you specify zero
or more -s ''blahblah'' arguments to set things up, then the specific
statement you want to time. Watch...:

[alex@lancelot pop]

timeit.py -s''import Numeric'' -s''x=Numeric.arange(555)''
''for i in x: id(i)''
1000 loops, best of 3: 296 usec per loop
[alex@lancelot pop]

timeit.py -s''import Numeric'' -s''x=range(555)'' ''for i in
x: id(i)''
1000 loops, best of 3: 212 usec per loop
[alex@lancelot pop]

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