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ANN: binario - simple work with binary files

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  ANN: binario - simple work with binary files bwatas@gmail.com - 2014-08-23 09:24 -0700
    Re: ANN: binario - simple work with binary files Rustom Mody <rustompmody@gmail.com> - 2014-08-23 20:13 -0700
    Re: ANN: binario - simple work with binary files Алексей Саскевич <bwatas@gmail.com> - 2014-08-25 02:58 -0700
      Re: ANN: binario - simple work with binary files Rustom Mody <rustompmody@gmail.com> - 2014-08-25 05:33 -0700
      Re: ANN: binario - simple work with binary files Mark Lawrence <breamoreboy@yahoo.co.uk> - 2014-08-25 14:20 +0100
    Re: ANN: binario - simple work with binary files Tim Roberts <timr@probo.com> - 2014-08-25 18:28 -0700
      Re: ANN: binario - simple work with binary files Rustom Mody <rustompmody@gmail.com> - 2014-08-25 20:45 -0700
        Re: ANN: binario - simple work with binary files Tim Roberts <timr@probo.com> - 2014-09-01 17:35 -0700
          Re: ANN: binario - simple work with binary files Rustom Mody <rustompmody@gmail.com> - 2014-09-01 21:35 -0700
            Re: ANN: binario - simple work with binary files Tim Roberts <timr@probo.com> - 2014-09-06 11:34 -0700

#76879 — ANN: binario - simple work with binary files

binario is the Python package that lets an application read/write primitive data types from an underlying input/output file as binary data.

Package on PyPI: https://pypi.python.org/pypi/binario
Package on GitHub: https://github.com/asaskevich/binario
Docs: http://binarios-docs.readthedocs.org/en/latest/

Package still in Alpha, and I need some help with testing, new features and docs :)

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#76920

On Saturday, August 23, 2014 9:54:05 PM UTC+5:30, Алексей Саскевич wrote:
> binario is the Python package that lets an application read/write primitive data types from an underlying input/output file as binary data.

> Package on PyPI: https://pypi.python.org/pypi/binario
> Package on GitHub: https://github.com/asaskevich/binario
> Docs: http://binarios-docs.readthedocs.org/en/latest/

> Package still in Alpha, and I need some help with testing, new features and docs :)

Any advantage of binario over construct?

http://construct.readthedocs.org/en/latest/basics.html

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#76972

Package works directly with files and has similar structure with Java's DataInputStream/DataOutputStream classes. 
Can construct read/write data from files?

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#76978

On Monday, August 25, 2014 3:28:28 PM UTC+5:30, Алексей Саскевич wrote:
> Package works directly with files and has similar structure with Java's DataInputStream/DataOutputStream classes. 
> Can construct read/write data from files?

I guess so. See parse_stream:
http://construct.readthedocs.org/en/latest/api/core.html

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#76980

On 25/08/2014 10:58, Алексей Саскевич wrote:
> Package works directly with files and has similar structure with Java's DataInputStream/DataOutputStream classes.
> Can construct read/write data from files?
>

Frankly I've no idea and without any context it's impossible to tell. 
What were you discussing and with whom?

-- 
My fellow Pythonistas, ask not what our language can do for you, ask
what you can do for our language.

Mark Lawrence

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#77017

bwatas@gmail.com wrote:
>
>binario is the Python package that lets an application read/write primitive data types from an underlying input/output file as binary data.
>
>Package on PyPI: https://pypi.python.org/pypi/binario
>Package on GitHub: https://github.com/asaskevich/binario
>Docs: http://binarios-docs.readthedocs.org/en/latest/
>
>Package still in Alpha, and I need some help with testing, new features and docs :)

I hope you will accept constructive criticism.

The documentation says it lets an application read/write binary data from
an "underlying input/output stream".  That's not really accurate.  "Stream"
implies something very general, but your constructors will only accept
filenames.  Your code ONLY works with files.  If I have a stream of data in
memory, or an already open file, your code can't be used.

This is why packages like "struct" (which is basically a more compact
version of what you are doing) read from a string or a buffer, and leave
the file-like behavior to things that already know how to behave like
files.

Compare your sample code:

  >>> import binario
  >>> r = binario.Reader("file.dat")
  >>> r.read_short()
  2014
  >>> r.read_bool()
  True
  >>> r.read_float()
  3.1415
  >>> r.read_string()
  "Hello, world!"
  >>> r.read(5)
  b'\x80\x14\n\xff\x00'

To the equivalent code with struct:

  import struct

  dscrp = "H?fs5B"

  f = open('file.dat')
  stuff = struct.unpack( dscrp, f.read() )

  print stuff

In both cases, you have to KNOW the format of the data beforehand.  If you
do a read_short where you happen to have written a float, disaster ensues.

I don't really see that you've added very much.
-- 
Tim Roberts, timr@probo.com
Providenza & Boekelheide, Inc.

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#77022

On Tuesday, August 26, 2014 6:58:42 AM UTC+5:30, Tim Roberts wrote:
> bwatas wrote:
> >binario is the Python package that lets an application read/write primitive data types from an underlying input/output file as binary data.
> >Package on PyPI: https://pypi.python.org/pypi/binario
> >Package on GitHub: https://github.com/asaskevich/binario
> >Docs: http://binarios-docs.readthedocs.org/en/latest/
> >Package still in Alpha, and I need some help with testing, new features and docs :)

> I hope you will accept constructive criticism.

> The documentation says it lets an application read/write binary data from
> an "underlying input/output stream".  That's not really accurate.  "Stream"
> implies something very general, but your constructors will only accept
> filenames.  Your code ONLY works with files.  If I have a stream of data in
> memory, or an already open file, your code can't be used.

> This is why packages like "struct" (which is basically a more compact
> version of what you are doing) read from a string or a buffer, and leave
> the file-like behavior to things that already know how to behave like
> files.

> Compare your sample code:

>   >>> import binario
>   >>> r = binario.Reader("file.dat")
>   >>> r.read_short()
>   2014
>   >>> r.read_bool()
>   True
>   >>> r.read_float()
>   3.1415
>   >>> r.read_string()
>   "Hello, world!"
>   >>> r.read(5)
>   b'\x80\x14\n\xff\x00'

> To the equivalent code with struct:

>   import struct

>   dscrp = "H?fs5B"

>   f = open('file.dat')
>   stuff = struct.unpack( dscrp, f.read() )

>   print stuff

> In both cases, you have to KNOW the format of the data beforehand.  If you
> do a read_short where you happen to have written a float, disaster ensues.

> I don't really see that you've added very much.

I thought much the same.
However notice your f.read(). Its type is string.

What if file.dat is a 1GB wav file?

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#77424

Rustom Mody <rustompmody@gmail.com> wrote:

>On Tuesday, August 26, 2014 6:58:42 AM UTC+5:30, Tim Roberts wrote:

>> To the equivalent code with struct:
>
>>   import struct
>
>>   dscrp = "H?fs5B"
>
>>   f = open('file.dat')
>>   stuff = struct.unpack( dscrp, f.read() )
>
>>   print stuff
>
>> In both cases, you have to KNOW the format of the data beforehand.  If you
>> do a read_short where you happen to have written a float, disaster ensues.
>
>> I don't really see that you've added very much.
>
>I thought much the same.
>However notice your f.read(). Its type is string.
>
>What if file.dat is a 1GB wav file?

  f.seek(512000)
  stuff = struct.unpack( dscrp, f.read(128) )

The point is that files already know how to position themselves.
-- 
Tim Roberts, timr@probo.com
Providenza & Boekelheide, Inc.

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#77432

On Tuesday, September 2, 2014 6:05:19 AM UTC+5:30, Tim Roberts wrote:
> Rustom Mody wrote:

> >On Tuesday, August 26, 2014 6:58:42 AM UTC+5:30, Tim Roberts wrote:

> >> To the equivalent code with struct:
> >>   import struct
> >>   dscrp = "H?fs5B"
> >>   f = open('file.dat')
> >>   stuff = struct.unpack( dscrp, f.read() )
> >>   print stuff
> >> In both cases, you have to KNOW the format of the data beforehand.  If you
> >> do a read_short where you happen to have written a float, disaster ensues.
> >> I don't really see that you've added very much.
> >I thought much the same.
> >However notice your f.read(). Its type is string.
> >What if file.dat is a 1GB wav file?

>   f.seek(512000)
>   stuff = struct.unpack( dscrp, f.read(128) )

And what if the struct you are (trying to) unpack is greater or less
than 128 bytes?

> The point is that files already know how to position themselves.

Sure.
But its not enough. One can write a generator that yields one char
at a time.  How to feed that to struct.unpack??

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#77663

Rustom Mody <rustompmody@gmail.com> wrote:

>On Tuesday, September 2, 2014 6:05:19 AM UTC+5:30, Tim Roberts wrote:
>> Rustom Mody wrote:
>
>> >On Tuesday, August 26, 2014 6:58:42 AM UTC+5:30, Tim Roberts wrote:
>
>> >> To the equivalent code with struct:
>> >>   import struct
>> >>   dscrp = "H?fs5B"
>> >>   f = open('file.dat')
>> >>   stuff = struct.unpack( dscrp, f.read() )
>> >>   print stuff
>> >> In both cases, you have to KNOW the format of the data beforehand.  If you
>> >> do a read_short where you happen to have written a float, disaster ensues.
>> >> I don't really see that you've added very much.
>> >I thought much the same.
>> >However notice your f.read(). Its type is string.
>> >What if file.dat is a 1GB wav file?
>
>>   f.seek(512000)
>>   stuff = struct.unpack( dscrp, f.read(128) )
>
>And what if the struct you are (trying to) unpack is greater or less
>than 128 bytes?

    stuff = struct.unpack( dscrp, f.read(struct.calcsize(dscrp)) )

>But its not enough. One can write a generator that yields one char
>at a time.  How to feed that to struct.unpack??

I think you have lost track of the discussion here, because your question
is irrelevant.  His binario package couldn't do that, either, since it only
accepts filenames.  But at least with struct.unpack, I can suck from the
generator into a string, and feed that string into struct.unpack.
-- 
Tim Roberts, timr@probo.com
Providenza & Boekelheide, Inc.

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