[Tutor] Need help printing a pickled data

[Matt D]

On 06/25/2013 10:33 PM, eryksun wrote:
> On Tue, Jun 25, 2013 at 8:35 PM, Matt D <md123 at nycap.rr.com> wrote:
>> so that code above is the wrapper of what the code below makes, which is
>> pickled data?:
>>
>> string
>> pickle::to_string() const
>> {
>>    size_t n = 1;
>>    ostringstream os;
>>    os << "(dp" << n++ << endl;
>>    for(stringmap::const_iterator i(map_.begin()); i != map_.end(); ++i) {
>>       os << "S'" << i->first << "'" << endl;
>>       os << "p" << n++ << endl;
>>       os << "S'" << i->second << "'" << endl;
>>       os << "p" << n++ << endl << "s";
>>    }
>>    os << "." << endl;
>>    return os.str();
>> }
> 
> That's a protocol 0 dict. Between MARK "(" and STOP "." is a DICT "d".
> Each key/value is a STRING "S". After pushing a key/value pair on the
> stack they're added to the dict by SETITEM "s". The PUT "p" operations
> store the stack top into the 'memo' (scratch array), but they seem
> superfluous since there's no matching GET (g).
> 
> For example:
> 
>     >>> pkl = "(dS'key1'\nS'val1'\nsS'key2'\nS'val2'\ns."
> 
>     >>> pickle.loads(pkl)
>     {'key2': 'val2', 'key1': 'val1'}
> 
>     >>> pickletools.dis(pkl)
>         0: (    MARK
>         1: d        DICT       (MARK at 0)
>         2: S    STRING     'key1'
>        10: S    STRING     'val1'
>        18: s    SETITEM
>        19: S    STRING     'key2'
>        27: S    STRING     'val2'
>        35: s    SETITEM
>        36: .    STOP
>     highest protocol among opcodes = 0
> 
> 
> FYI, this appears to be the repository for the above C++
> (pickle::to_string, hdu::snapshot):
> 
> http://op25.osmocom.org/trac/wiki.png/browser/trunk/blocks/src/lib
> 
> But I've only glanced at the code and don't know GNU Radio from GNU Gnews.
> 
Thanks!
Yes I am working with a decoder used in GNU radio.  Python is used for
the UI while the computationally intense stuff is done in C++ blocks.
Trying to learn this hybrid C++/Python system really is a crash course.