# Extract Indices of Numpy Array Based on Given Bit Information

Artur Bercik vbubbly21 at gmail.com
Sat Oct 18 09:21:02 CEST 2014

```On Sat, Oct 18, 2014 at 4:10 PM, Chris Angelico <rosuav at gmail.com> wrote:

> On Sat, Oct 18, 2014 at 6:02 PM, Artur Bercik <vbubbly21 at gmail.com> wrote:
> > So, the  Bit No. 2-5 for the following case is '1101', right?
> >
> > 1073741877: 1000000000000000000000000110101
> >
> >  If my required bit combination for Bit No. 2-5 is '1011', then the above
> > number (1073741877) is not chosen, right??
> >
> > Look forward to know your confirmation.
>
> (Side point: Please don't top-post. The convention on this mailing
> list, and most other technical mailing lists, is what's sometimes
> called "interleaved style"; you trim the quoted text to what's needed
> for context, and put your text underneath what you're referring to.
> See https://en.wikipedia.org/wiki/Posting_style#Interleaved_style for
>
> >>> 1073741877&60
> 52
> >>> bin(52)
> '0b110100'
>
> Everything I've written with the triple-angle-bracket marker can be
> typed in at the Python prompt, and you'll see exactly what it does. In
> this case, you can see that you're absolutely right: 1073741877 has
> 1101 in those positions, so if you're looking for 1011, it won't
> match:
>
> >>> 0b101100
> 44
>
> However, 1073741869 would:
>
> >>> 1073741869&60
> 44
>
> The way to test would be something like this:
>
> >>> (1073741877 & 0b111100) == 0b101100
> False
> >>> (1073741869 & 0b111100) == 0b101100
> True
>

Thank you very much Chris Angelico, I have come to know it.

>
> ChrisA
> --
> https://mail.python.org/mailman/listinfo/python-list
>
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