[C++-sig] Renaming "<string>" filename for PyRun_String

[David Faure]

Victor Nakoryakov <nail-mail at mail.ru> wrote:
> I use PyRun_String to run script stored in some file. I can't use
> PyRun_File because of different layouts of FILE struct in my project and
> in python lib. So once I get error I see something like:
>
> Traceback (most recent call last):
>    File "<string>", line 14, in ?
> NameError: ...
>
> Is it possible somehow to rename "<string>" in this message to the real filename?

I just had the same problem, and I solved it by copying some code out of the pythonrun.c sources...

[This means it would be nice for the python developers to provide a PyRun_StringFileName().
Just like it would be nice to have a public function that calls tb_printinternal, parse_syntax_error, etc
in order to print out all the info about a parsing or runtime error just like python itself does.]

Anyway; this code does the job for me:

#include <node.h> // from python

// Copied from pythonrun.c
static PyObject *run_node(struct _node *n, const char *filename, PyObject *globals, PyObject *locals, PyCompilerFlags *flags) {
    PyCodeObject *co;
    PyObject *v;
    co = PyNode_CompileFlags(n, filename, flags);
    PyNode_Free(n);
    if (co == NULL)
        return NULL;
    v = PyEval_EvalCode(co, globals, locals);
    Py_DECREF(co);
    return v;
}

// This is missing from python: a PyRun_String that also takes a filename, to show in backtraces
static PyObject* MyPyRun_StringFileName(const char *str, const char* filename, int start, PyObject *globals, PyObject *locals) {
    struct _node* n = PyParser_SimpleParseString(str, start);
    if (!n) return 0;
    return run_node( n, filename, globals, locals, 0 );
}


-- 
David Faure -- faure at kde.org, dfaure at klaralvdalens-datakonsult.se
KDE/KOffice developer, Qt consultancy projects
Klarälvdalens Datakonsult AB, Platform-independent software solutions