a=0100; print a ; 64 how to reverse this?

[mosi]

Problem:
how to get binary from integer and vice versa?
The simplest way I know is:
a = 0100
a
64

but:
a = 100 (I want binary number)
does not work that way.

a.__hex__   exists
a.__oct__ exists

but where is a.__bin__ ???


What`s the simplest way to do this?
Thank you very much.

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Re: a=0100; print a ; 64 how to reverse this?

[mosi]

Thank you,
this is great,
I thought that this should be standard in python 2.4 or 2.5 or in some
standard library (math ???)
Didn`t find anything.


On Jul 17, 2:05 pm, John Machin <[EMAIL PROTECTED]> wrote:
> On Jul 17, 9:09 pm, mosi <[EMAIL PROTECTED]> wrote:
>
>
>
> > Problem:
> > how to get binary from integer and vice versa?
> > The simplest way I know is:
> > a = 0100
> > a
> > 64
>
> > but:
> > a = 100 (I want binary number)
> > does not work that way.
>
> > a.__hex__   exists
> > a.__oct__ exists
>
> > but where is a.__bin__ ???
>
> > What`s the simplest way to do this?
> > Thank you very much.
>
> Here's a sketch; I'll leave you to fill in the details -- you may wish
> to guard against interesting input like b < 2.
>
> >>> def anybase(n, b, digits='0123456789abcdef'):
>
> ...tmp = []
> ...while n:
> ...   n, d = divmod(n, b)
> ...   tmp.append(digits[d])
> ...return ''.join(reversed(tmp))
> ...>>> anybase(1234, 10)
> '1234'
> >>> anybase(7, 2)
> '111'
> >>> [anybase(64, k) for k in range(2, 17)]
>
> ['100', '2101', '1000', '224', '144', '121', '100', '71', '64',
> '59', '54', '4c', '48', '44', '40']
>
>
>
> HTH,
> John


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Any way to program custom syntax to python prompt? >> I want to edit matrices.

[mosi]

Python matrices are usually defined with numpy scipy array or similar.
e.g.
>>> matrix1 = [[1, 2], [3, 4], [5, 6]]
I would like to have easier way of defining matrices,
for example:
>>> matrix = [1, 2; 3, 4; 5, 6]

>>> matrix =
[ 1, 2;
  3, 4;
  5, 6;]

Any ideas how could this be done? The ";" sign is reserved, the "[ ]"
is used for lists.

Also, how to program custom operations for this new "class?"
matrix ???

For example:
>>> matrix + 2
[ 3, 4;
  5, 6;
  7, 8;]

Possibly with operator overloading?
I appreciate all your comments, directions, pointers.
mosi
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