Re: [HACKERS] adding import in pl/python function
On Fri, 2013-05-24 at 16:46 -0300, Claudio Freire wrote: Well, it's easy. Instead of PLyFloat_FromNumeric[0], you can make a PLyDecimal_FromNumeric. Please send a patch. This would be a welcome addition. -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
Re: [HACKERS] adding import in pl/python function
On Mon, May 27, 2013 at 8:13 PM, Peter Eisentraut pete...@gmx.net wrote: On Fri, 2013-05-24 at 16:46 -0300, Claudio Freire wrote: Well, it's easy. Instead of PLyFloat_FromNumeric[0], you can make a PLyDecimal_FromNumeric. Please send a patch. This would be a welcome addition. I can write it blind as I have more than enough experience with CPython, but I don't use PLPython so I can't perform extensive testing. If someone's willing to do the testing, by all means. -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
Re: [HACKERS] adding import in pl/python function
On Mon, 2013-05-27 at 20:43 -0300, Claudio Freire wrote: On Mon, May 27, 2013 at 8:13 PM, Peter Eisentraut pete...@gmx.net wrote: On Fri, 2013-05-24 at 16:46 -0300, Claudio Freire wrote: Well, it's easy. Instead of PLyFloat_FromNumeric[0], you can make a PLyDecimal_FromNumeric. Please send a patch. This would be a welcome addition. I can write it blind as I have more than enough experience with CPython, but I don't use PLPython so I can't perform extensive testing. If someone's willing to do the testing, by all means. Yes please. -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
Re: [HACKERS] adding import in pl/python function
On 28 May 2013 01:55, Peter Eisentraut pete...@gmx.net wrote: On Mon, 2013-05-27 at 20:43 -0300, Claudio Freire wrote: On Mon, May 27, 2013 at 8:13 PM, Peter Eisentraut pete...@gmx.net wrote: On Fri, 2013-05-24 at 16:46 -0300, Claudio Freire wrote: Well, it's easy. Instead of PLyFloat_FromNumeric[0], you can make a PLyDecimal_FromNumeric. Please send a patch. This would be a welcome addition. I can write it blind as I have more than enough experience with CPython, but I don't use PLPython so I can't perform extensive testing. If someone's willing to do the testing, by all means. Yes please. I'm working on that. - Szymon
[HACKERS] adding import in pl/python function
Hi, I'm wondering if it would be OK to change the procedure code before execution. I'm thinking about adding magically an import at the beginning of a function. Currently numeric arguments passed to the procedure are converted into floats. This is not good, as it causes loss of information. The proposed solution in code comment is maybe use a string?. I'm thinking about something else. We could convert it into Decimal ( http://docs.python.org/2/library/decimal.html) class in Python. Unfortunately this class requires import like `from decimal import Decimal` from a standard Python library. I'm wondering if it would be a good idea to do it like this. It shouldn't fail even with the trusted version of pl/python, as I'd rather see the trusted version to allow importing packages from standard library. regards, Szymon
Re: [HACKERS] adding import in pl/python function
On Fri, May 24, 2013 at 4:10 PM, Szymon Guz mabew...@gmail.com wrote: I'm thinking about something else. We could convert it into Decimal (http://docs.python.org/2/library/decimal.html) class in Python. Unfortunately this class requires import like `from decimal import Decimal` from a standard Python library. I'm wondering if it would be a good idea to do it like this. It shouldn't fail even with the trusted version of pl/python, as I'd rather see the trusted version to allow importing packages from standard library. Why would passing a decimal require an import? The extension itself needs a reference to Decimal, to build them, but the procedure's context doesn't need to have it. -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
Re: [HACKERS] adding import in pl/python function
On 24 May 2013 21:14, Claudio Freire klaussfre...@gmail.com wrote: On Fri, May 24, 2013 at 4:10 PM, Szymon Guz mabew...@gmail.com wrote: I'm thinking about something else. We could convert it into Decimal (http://docs.python.org/2/library/decimal.html) class in Python. Unfortunately this class requires import like `from decimal import Decimal` from a standard Python library. I'm wondering if it would be a good idea to do it like this. It shouldn't fail even with the trusted version of pl/python, as I'd rather see the trusted version to allow importing packages from standard library. Why would passing a decimal require an import? The extension itself needs a reference to Decimal, to build them, but the procedure's context doesn't need to have it. Hm... maybe you're right. I think I don't understand fully how the procedures are executed, and I need to read more to get it. thanks, Szymon
Re: [HACKERS] adding import in pl/python function
On Fri, May 24, 2013 at 4:22 PM, Szymon Guz mabew...@gmail.com wrote: Hm... maybe you're right. I think I don't understand fully how the procedures are executed, and I need to read more to get it. Well, it's easy. Instead of PLyFloat_FromNumeric[0], you can make a PLyDecimal_FromNumeric. There, you'd do with the Python/C[1]: PyObject *decimal = PyImport_Import(decimal); PyObject *decimal_dict = PyModule_GetDict(decimal); PyObject *decimal_ctor = PyDict_GetItemString(decimal_dict, Decimal); And invoke it with a string rep of your Numeric: PyObject *value = PyObject_CallFunction(decimal_ctor, S, string_value); Add of course all kinds of error checking and reference count boiler plate, and you'd have a very dumb version of it. To make it more pro, you'd want to do all that stuff to get decimal_ctor only at initialization time. Especially since you don't want to fumble with the import lock right there in _FromNumeric. And to make it totally pro, you can even freeze Decimal (using pyfreeze) if you'd like. I would only do this in contexts where you don't have a stdlib of course. Not sure whether windows falls into that category. Linux doesn't. [0] http://git.postgresql.org/gitweb/?p=postgresql.git;a=blob;f=src/pl/plpython/plpy_typeio.c#l518 [1] http://docs.python.org/2/c-api/import.html -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
Re: [HACKERS] adding import in pl/python function
On 24 May 2013 21:46, Claudio Freire klaussfre...@gmail.com wrote: On Fri, May 24, 2013 at 4:22 PM, Szymon Guz mabew...@gmail.com wrote: Hm... maybe you're right. I think I don't understand fully how the procedures are executed, and I need to read more to get it. Well, it's easy. Instead of PLyFloat_FromNumeric[0], you can make a PLyDecimal_FromNumeric. There, you'd do with the Python/C[1]: PyObject *decimal = PyImport_Import(decimal); PyObject *decimal_dict = PyModule_GetDict(decimal); PyObject *decimal_ctor = PyDict_GetItemString(decimal_dict, Decimal); And invoke it with a string rep of your Numeric: PyObject *value = PyObject_CallFunction(decimal_ctor, S, string_value); Add of course all kinds of error checking and reference count boiler plate, and you'd have a very dumb version of it. To make it more pro, you'd want to do all that stuff to get decimal_ctor only at initialization time. Especially since you don't want to fumble with the import lock right there in _FromNumeric. And to make it totally pro, you can even freeze Decimal (using pyfreeze) if you'd like. I would only do this in contexts where you don't have a stdlib of course. Not sure whether windows falls into that category. Linux doesn't. [0] http://git.postgresql.org/gitweb/?p=postgresql.git;a=blob;f=src/pl/plpython/plpy_typeio.c#l518 [1] http://docs.python.org/2/c-api/import.html Thanks, I will take a look at this, looks pretty easy. However testing on Windows will be pretty funny :) thanks, Szymon
