C API - How to return a Dictionary as a Dictionary type

[Jen Kris]

Yes, that works.  This is my first day with C API dictionaries.  Now that you've explained it, it makes perfect sense.  Thanks much.  

Jen


Feb 14, 2022, 17:24 by rosuav at gmail.com:

> On Tue, 15 Feb 2022 at 12:07, Jen Kris via Python-list
> <python-list at python.org> wrote:
>
>>
>> I created a dictionary with the Python C API and assigned two keys and values:
>>
>> PyObject* this_dict = PyDict_New();
>> const char *key = "key1";
>> char *val = "data_01";
>> PyObject* val_p = PyUnicode_FromString(val);
>> int r = PyDict_SetItemString(this_dict, key, val_p);
>>
>> // Add another k-v pair
>> key = "key2";
>> val = "data_02";
>> val_p = PyUnicode_FromString(val);
>> r = PyDict_SetItemString(this_dict, key, val_p);
>>
>> I need to retrieve the entire dictionary to be passed to a library function that expects a dictionary.  I used  PyDict_Items:
>>
>> PyObject* pdi = PyDict_Items(this_dict);
>> PyObject* str_untagd = PyObject_Str(pdi);
>> PyObject* repr_utd = PyObject_Repr(str_untagd);
>> PyObject* str_utd = PyUnicode_AsEncodedString(repr_utd, "utf-8", "~E~");
>> const char *bytes_d = PyBytes_AS_STRING(str_utd);
>> printf("REPR_UnTag: %s\n", bytes_d);
>>
>> but as the docs say (https://docs.python.org/3.8/c-api/dict.html), that returns a PyListObject, not a dictionary enclosed with curly braces:
>>
>> [('key1', 'data_01'), ('key2', 'data_02')]".
>>
>> My question is, how can I get the dictionary as a dictionary type, enclosed with curly braces.  I found PyObject_GenericGetDict (https://docs.python.org/3.8/c-api/object.html) but I haven't found any documentation or explanation of how it works.
>>
>> Is PyObject_GenericGetDict what I need, or is there another way to do it?
>>
>
> Not sure what you mean. The dict is already a dict. If you refer to
> this_dict, it is a dict, right?
>
> If you need the string representation of that, you should be able to
> call PyObject_Repr just as you are, but call it on the dict, not on
> the dict items.
>
> ChrisA
> -- 
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>